In contact forces, _____.
A.) objects do not touch each other
B.) objects must touch each other
C.) more work is done than in other forces
Answer:
B is the best answer for this
Why evaporation takes place from the Surface?
Answer:
in the water cycle evaporation occurs when the sunlight warms the surface of the water the heat from the sun makes the water molecules move faster and faster until they move so fast they can escape as a gas once evaporated a molecule from water that vapor spends about 10 days in the air
The earliest mineral observed to showmagnetic properties is called
A leadstone
Blodestone
Cloadstone
Dnone of the above
E all of the above
Answer:
B: lodestone
Explanation:
Each magnet has its magnetic poles, north (N) and south (S). Diversified ones are attracted and reptiles of the same name are repelled, similarly to charges, so it was considered possible to separate the magnet at the north and south poles.
Magnetic properties can be lost if the magnet is exposed to high temperatures if it falls or due to some mechanical shocks.
A man walks south at a speed of 2.00 m/s for 60.0 minutes. He then turns around and walks north a distance 3000 m in 25.0 minutes. What is the average velocity of the man during his entire motion?
Answer:
v = 0.823 m/s
Explanation:
A man walks south at a speed of 2.00 m/s for 60.0 minutes.
The distance covered in South = 60 × 60 × 2 = 7200 m
He then turns around and walks north a distance 3000 m in 25.0 minutes.
As they moved in opposite direction, net displacement will be : 7200 - 3000 = 4200 m
Average velocity of the man = net displacement/time
[tex]v=\dfrac{4200\ m}{(60+25)\times 60}\\\\=0.823\ m/s[/tex]
So, the average velocity of the man is 0.823 m/s.
What is the current in the wire now?
Answer:
220v
Explanation:
Sorry, the question is incomplete
Answer:
on the potential difference applied and on the resistance of the wire.
Explanation:
Ohms law state that the current through a conductor between two points is directly proportional to the potential difference across the two points. Imtroducing the comstant of proportionality, the resistance, one arrives at the usual athematical equation that describes this relationship: I = V/R.
. A crane does 62,500 joules of work to lift a boulder a distance of 25.0 meters. How much did the boulder
weigh? (Hint: The weight of an object is considered to be a force in units of newtons.)
13
Answer:
2500 NExplanation:
The weight of the object can be found by using the formula
[tex]f = \frac{w}{d} \\ [/tex]
w is the workdone
d is the distance
From the question we have
[tex]f = \frac{62500}{25} \\ [/tex]
We have the final answer as
2500 NHope this helps you
A 4.8-g particle is moving toward a stationary 7.4-g particle at 3.0 m/s. What percentage of the original kinetic energy is convertible to internal energy?
Answer:
60.185 percent of the original kinetic energy is convertible to internal energy.
Explanation:
Let suppose that collision between both particles is entirely inellastic. If there is no external forces exerted on any of the particles, then we can apply the Principle of Linear Momentum Conservation. That is:
[tex]m_{A}\cdot v_{A,o} + m_{B}\cdot v_{B,o} = (m_{A}+m_{B})\cdot v[/tex]
[tex]v = \frac{m_{A}\cdot v_{A,o}+v_{B}\cdot v_{B,o}}{m_{A}+m_{B}}[/tex] (1)
Where:
[tex]m_{A}[/tex] - Mass of the 4.8-g particle, measured in kilograms.
[tex]m_{B}[/tex] - Mass of the 7.4-g particle, measured in kilograms.
[tex]v_{A,o}[/tex] - Initial speed of the 4.8-g particle, measured in meters per second.
[tex]v_{B,o}[/tex] - Initial speed of the 7.4-g particle, measured in meters per second.
[tex]v[/tex] - Final speed of the collided particles, measured in meters per second.
If we know that [tex]m_{A} = 4.8\times 10^{-3}\,kg[/tex], [tex]m_{B} = 7.4\times 10^{-3}\,kg[/tex], [tex]v_{A,o} = 3\,\frac{m}{s}[/tex] and [tex]v_{B,o} = 0\,\frac{m}{s}[/tex], then the final speed of the system is:
[tex]v = \frac{(4.8\times 10^{-3}\,kg)\cdot \left(3\,\frac{m}{s} \right)+(7.4\times 10^{-3}\,kg)\cdot \left(0\,\frac{m}{s} \right)}{4.8\times 10^{-3}\,kg+7.4\times 10^{-3}\,kg}[/tex]
[tex]v = 1.180\,\frac{m}{s}[/tex]
During the collision part of the initial energy is dissipated in the form of heat, which is related to the internal energy ([tex]\Delta U[/tex]), measured in joules. According to the Principle of Energy Conservation, we have the following model:
[tex]\Delta U = K_{A}+K_{B}-K[/tex] (2)
Where:
[tex]K_{A}[/tex], [tex]K_{B}[/tex] - Initial translational kinetic energies of each particle, measured in joules.
[tex]K[/tex] - Final translational kinetic energy of the collided particles, measured in joules.
By applying the definition of translational kinetic energy, we expand and simplify the equation above:
[tex]\Delta U = \frac{1}{2}\cdot m_{A}\cdot v_{A,o}^{2}+\frac{1}{2}\cdot m_{B}\cdot v_{B,o}^{2} -\frac{1}{2}\cdot (m_{A}+m_{B})\cdot v^{2}[/tex] (3)
If we get that [tex]m_{A} = 4.8\times 10^{-3}\,kg[/tex], [tex]m_{B} = 7.4\times 10^{-3}\,kg[/tex], [tex]v_{A,o} = 3\,\frac{m}{s}[/tex], [tex]v_{B,o} = 0\,\frac{m}{s}[/tex] and [tex]v = 1.180\,\frac{m}{s}[/tex], the internal energy associated with the system is:
[tex]\Delta U = \frac{1}{2}\cdot (4.8\times 10^{-3}\,kg)\cdot \left(3\,\frac{m}{s} \right)^{2}+ \frac{1}{2}\cdot (7.4\times 10^{-3}\,kg)\cdot \left(0\,\frac{m}{s} \right)^{2}-\frac{1}{2}\cdot (4.8\times 10^{-3}\,kg+7.4\times 10^{-3}\,kg)\cdot \left(1.180\,\frac{m}{s} \right)^{2}[/tex]
[tex]\Delta U = 0.013\,J[/tex]
And the initial energy of both particles is:
[tex]E_{o} = \frac{1}{2}\cdot (4.8\times 10^{-3}\,kg)\cdot \left(3\,\frac{m}{s}\right)^{2}+\frac{1}{2}\cdot (7.4\times 10^{-3}\,kg)\cdot \left(0\,\frac{m}{s} \right)^{2}[/tex]
[tex]E_{o} = 0.0216\,J[/tex]
Lastly, the percentage of the original kinetic energy that is convertible to internal energy is: ([tex]\Delta U = 0.013\,J[/tex], [tex]E_{o} = 0.0216\,J[/tex])
[tex]\%e = \frac{\Delta U}{E_{o}}\times 100\,\%[/tex] (4)
[tex]\%e = \frac{0.013\,J}{0.0216\,J}\times 100\,\%[/tex]
[tex]\%e = 60.185\,\%[/tex]
60.185 percent of the original kinetic energy is convertible to internal energy.
answer? physics Q for 3rd secondary..
Answer:
The 300 Ohm resistor
Explanation:
They are in series, so the current has to be the same in both. P = I^2R, so with the same current, the larger resistor dissipates more power.
premium
A student releases a marble from the top of a ramp. The marble increases speed
while on the ramp then continues across the floor. The marble travels a total of
150cm in 4.80s.
What was the marble's final speed?
Explanation:
the formula of speed is distance traveled by time it work
31.25 cm/sec
__________________________________________________________
Explanation:We are given:
Distance travelled = 150 cm
Time taken = 4.8 seconds
Final Speed of the Marble:
Speed of the marble = Distance travelled / Time taken
Speed of the marble = 150 / 4.8
Speed of the marble = 31.25 cm/sec
At noon on a clear day, sunlight reaches the earth's surface at Madison, Wisconsin, with an average intensity of approximately 2.00 kJ·s−1·m^−2. If the sunlight consists of photons with an average wavelength of 510.0 nm, how many photons strike a 5.20 cm^2 area per second?
Answer:
The number of photons per second that strike the given area is 2.668 x 10⁸ photons/second
Explanation:
Given;
intensity of the sunlight, I = 2.00 kJ·s−1·m^−2
area of incident, A = 5.2 cm² = 5.2 x 10⁻⁴ m²
Energy of incident photons per second on the given area;
E = IA
E = (2000)( 5.2 x 10⁻⁴)
E = 1.04 J/s
Energy of a photon is given is by;
[tex]E = \frac{hc}{\lambda} \\\\E = \frac{(6.626*10^{-34})(3*10^8)}{(510*10^{-9})}\\\\E = 3.898*10^{-19} \ J/photon[/tex]
The number of photons per second that strike the given area is;
[tex]n = \frac{1.04 \ J/s}{3.898*10^{-19} \ J/photon} \\\\n = 2.668*10^{18} \ photons/second[/tex]
Therefore, the number of photons per second that strike the given area is 2.668 x 10⁸ photons/second
Which current is produced in homes
Answer:
answer is C on edge 2021
Explanation:
The angle of incidence is the angle between the the normal of the surface. and A. point of incidence B. reflected ray C. incident ray D. refracted ray
Answer: c. incident ray
Explanation:
A ball is kicked off the ground reaching a maximum height of 60m and lands 80m away. Calculate the initial speed and the angle above the horizontal of the ball when it was kicked
Answer:
36.87°
Explanation:
Given
Maximum height = 60m
Horizontal distance (range) = 80,m
Required
Initial speed U
Angle of launch
To get the speed, we will use the range formula;
R = U √2H/g
80 = U√2(60)/9.8
80 = U√12.25
80 = 3.5U
U = 80/3.5
U = 22.86m/s
Get the angle of launch
Using the formula
Theta = tan^-1(y/x)
y is the vertical distance
x is the horizontal distance
Theta = tan^-1(60/80)
Theta = tan^-1(0.75)
Theta = 36.87°
Hence the angle of launch is 36.87°
How much work would be done on a particle with 5.0 C of charge on it if it moved from an equipotential line at 5.5 volts to another equipotential line at 3.5 volts?
Answer:
10J
Explanation:
In this question we have the following information
The charge of the particle is q = 5 C
The equipotenetial level is V1 = 5.5 v
and also the
equipotenetial level is V2 = 3.5 v
So we calculate the
work done W=q x (v1-v2)
workdone = 5 x (5.5-3.5)
= 5x2
=10 J
Workdone = 10 J
So we conclude that the workdone on a particle with these information is 10j
A scientist decides to replicate an experiment completed by another scientist. Which statement describes something that would not affect the results of the replicated experiment
Hi, you've asked an incomplete question. However, I provided some explanation about the replication process that scientists do.
Explanation:
Replication in research involves carefully repeating an original experiment to see whether the same result would be arrived at as in previous research experiments.
For most scientists today, in other to avoid anything that would erroneously affect the results of the replicated experiment they usually follow the same procedures as carried by the previous researchers.
A car is traveling at 60 mph. If the rate of speed increases 4 mph each hour,
how long will it be before the car is traveling at a rate of 80 mph?
A) 4 hours
B) 5 hours
C) 6 hours
D 7 hours
Answer:
5 hours ................
Answer:
B=5 hrs
explanation:
becoz if you add 4 mph/hr
it will graually be 80 in 5 hrs
A relaxed spring of length 0.15 m stands vertically on the floor; its stiffness is 1070 N/m. You release a block of mass 0.5 kg from rest, with the bottom of the block 0.6 m above the floor and straight above the spring. How long is the spring when the block comes momentarily to rest on the compressed spring?
Answer:
x' = 0.085 m = 8.5 cm
Explanation:
The law of conservation of energy says that:
Potential Energy Stored in Spring = Loss in Gravitational Potential Energy of Block
(1/2)kΔx² = mgh
where,
k = stiffness of spring = 1070 N/m
Δx = change in length of spring = ?
m = mass of block = 0.5 kg
g = 9.8 m/s²
h = height of block above spring = 0.6 m - 0.15 m = 0.45 m
Therefore,
(1/2)(1070 N/m)Δx² = (0.5 kg)(9.8 m/s²)(0.45 m)
Δx = √[2(2.205 Nm)/(1070 N/m)]
Δx = 0.064 m
but,
Δx = x - x' = 0.15 m - x' = 0.064 m
x' = 0.15 m - 0.064 m
x' = 0.085 m = 8.5 cm
A block slides down an inclined plane. Which force does zero work?
a. normal force
b. friction
c. the weight
d. all of the above
e. none of the above
Answer:
e
Explanation:
cause you have any attachments are not sure if you can get it
When a block slides down an inclined plane, normal force does zero work. Hence, option (a) is correct.
What is force?The definition of force in physics is: The push or pull on a massed object changes its velocity.
An external force is an agent that has the power to alter the resting or moving condition of a body. It has a direction and a magnitude. A spring balance can be used to calculate the Force. The Newton is the SI unit of force.
The component of a contact force in mechanics known as the normal force is perpendicular to the surface that an item encounters.
As normal force always acts perpendicular to the motion, this force does zero work.
But friction force the weight acts in opposite direction of the motion, this force does work against the motion.
In an inclined plane, the parallel component of weight does work along the motion.
Learn more about normal force here:
https://brainly.com/question/18799790
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A circular disk of radius 2.0 m rotates, starting from rest, with a constant angular acceleration of 20.0 rad/s2. What is the tangential acceleration of a point on the edge of the disk at the instant that its angular speed is 1.0 rev/s?a. 40 m/s2.
b. 79 m/s2.
c. zero m/s2.
d. 120 m/s2.
e. 110 m/s2.
Answer:
Option (a) is correct.
Explanation:
Given that,
The radius of a circular disk, r = 2 m
Angular acceleration, [tex]\alpha =2\ rad/s^2[/tex]
We need to find the tangential acceleration of a point on the edge of the disk at the instant that its angular speed is 1.0 rev/s.
Let a is the tangential acceleration. The relation between the angular acceleration and tengential acceleration. Let it is a.
[tex]a=\alpha r\\\\a=20\times 2\\\\a=40\ m/s^2[/tex]
So, the tangential acceleration is [tex]40\ m/s^2[/tex].
A baseball is thrown across the field. The ____________is measured from where the ball is thrown to where landed was 75 feet.
motion
direction
distance
reference point
Answer:
distance i think
Explanation:
How do the magnetic fields of Uranus and Neptune suggest that the mantles inside those planets are fluid?
Answer:
The surface must be a good absorber of light. Spectra of the planets proved that methane in the atmospheres of these planets is what absorbs red light.
Explanation:
A solid spherical ball and a hollow spherical ball made out of the same material are released from rest at the top of a ramp. They roll down the ramp without slipping to the bottom. On what quantities does the speed of each ball at the bottom of the ramp depend?A. Radius of the ball.B. Distribution of mass within the ball.C. Mass of the ball.D. Height of the ramp.
Answer:
D. Height of the ramp.
Explanation:
The solid spherical ball is expected to have more mass than that of the hollow spherical ball. And the speed of both balls would be influenced by the gravitational force as they roll down the ramp. Thus, the masses would move at different speed.
At the bottom of the ramp, the speed of the balls can be varied by varying the height of the ramp. So that the speed of both balls depend on the height of the ramp. As the height of the ramp increases, consequently, the speed of the balls increases. And if the height of the ramp decreases, the speed of the balls decreases consequently.
"2.40 A pressure of 4 × 106N/m2 is applied to a body of water that initially filled a 4300 cm3 volume. Estimate its volume after the pressure is applied."
Answer:Final volume after pressure is applied=4,292cm3
Explanation:
Using the bulk modulus formulae
We have that The bulk modulus of waTer is given as
K =-V dP/dV
Where K, the bulk modulus of water = 2.15 x 10^9N/m^2
2.15 x 10^9N/m^2= - 4,300 x 4 × 106N/m2 / dV
dV = - 4,300 x 4 × 10^6N/m^2/ 2.15 x 10^9N/m^2
dV (change in volume)= -8.000cm^3
Final volume after pressure is applied,
V= V+ dV
V= 4300cm3 + (-8.000cm3)
=4300cm3 - 8.000cm3
Final Volume, V =4,292cm3
What did Isaac Newton’s investigation if the gravity explain ?
Answer:
Gravity acts on all objects in the universe.
Explanation:
Two objects attract each other with a gravitational force of magnitude 1.01 10-8 N when separated by 19.9 cm. If the total mass of the two objects is 5.11 kg, what is the mass of each?
Answer:
m₂ = 1.17 kg
Explanation:
Given that,
Force between two objects, [tex]F=1.01\times 10^{-8}\ N[/tex]
Mass of object 1, [tex]m_1=5.11\ kg[/tex]
Distance between masses, r = 19.9 cm = 0.199 m
The gravitational force between two masses is given by :
[tex]F=\dfrac{Gm_1m_2}{r^2}[/tex]
m₂ is the mass of object 2
[tex]m_2=\dfrac{Fr^2}{Gm_1}\\\\m_2=\dfrac{1.01\times 10^{-8}\times (0.199)^2}{6.67\times 10^{-11}\times 5.11}\\\\=1.17\ kg[/tex]
So, the mass of second object is 1.17 kg.
Consider a person standing in an elevator that is moving at a constant velocity down. The upward normal force N exerted by the elevator floor on the person is Select one: a. smaller than the downward force of gravity on the person. b. identical to the downward force of gravity on the person. c. larger than the downward force of gravity on the person.
Answer:
b. identical to the downward force of gravity on the person.
Explanation:
For an object in an elevator,
F = mg - ma (g > a)
But since the velocity is uniform, a = 0.
Then,
F = mg - 0
F = mg
This is the actual weight of the object.
The object does not feel weightless, so that its actual weight can be measured during the downward motion of the elevator with uniform velocity.
Thus, the upward normal force, N, exerted by the elevator floor on the person is identical to the downward force of gravity on the person.
While riding a multispeed bicycle, the rider can select the radius of the rear sprocket that is fixed to the rear axle. The front sprocket of a bicycle has radius 12.0 cm. If the angular speed of the front sprocket is 0.600 rev/s, what is the radius of the rear sprocket for which the tangential speed of a point on the rim of the rear wheel will be 5.00 m/s?
Answer:
2.9 cm
Explanation:
Assuming that the rear wheel has a radius of 0.330 m
Given that
r(a) = 12 cm -> 0.12 m
w(a) = 0.6 rev/s -> 3.77 rad/s
v = 5 m/s
r(w) = 0.330 m
The speed on any point on the rim at the sprocket in the front is
v(a) = w(a).r(a) = 3.77 * 0.12 = 0.4524 m/s
Also,
v(a) = speed at any point on the chain
v(b) = speed at any point on the rim of the rear sprocket
v(a) = v(b)
where v(b) = w(b).r(b)
Recall that the speed at any point on the rear wheel is v, where
v = w(b).r(w)
5 = w(b) * 0.330
w(b) = 5/0.330
w(b) = 15.15 rad/s
On substituting this in the equation, we have
v(b) = w(b).r(b).
Remember also, that v(a) = v(b), so
0.4524 = 15.15 * r(b)
r(b) = 0.4524 / 15.15
r(b) = 0.029 m -> 2.9 cm
Therefore, the radius of the rear sprocket needed is 2.9 cm
During the stretching routine who used the medicine ball for support.
The guy
The guy
The Girl
The Girl
Both people used a ball for support
Both people used a ball for support
No one used it
No one used it
A rock dropped from a 5 m height accelerates at 10 m/s and strikes the ground 1 s later. If the rock is dropped
from a height of 2,5 m, its acceleration of fall is
Answer:
10 m/s²
Explanation:
The above question simply indicates motion under gravity.
The acceleration due to gravity (i.e acceleration of free fall) has a constant value of 10 m/s².
Whether the rock is dropped from a height of 5 m or 2.5 m, it will accelerate at 10 m/s² before striking the ground. The only thing that will be different is the time taken for the rock to strike the ground when released from both 5 m and 2.5 m.
Thus, the rock will have a constant acceleration of 10 m/s² irrespective of the height to which it was released.
Since acceleration due to gravity is a constant, the acceleration of the rock dropped from the 5 m height is the same as that dropped from the 2.5 m height and is equal to 10 m/s²
What is the acceleration due to gravity?Acceleration due to gravity is the acceleration a body falling freely from a height above the earth surface which a body experiences due to the gravitational force of attraction of the earth on the body.
Acceleration due to gravity has a constant value which is equal to 10 m/s².
Therefore, the acceleration of the rock dropped from the 5 m height is the same as that dropped from the 2.5 m height and is equal to 10 m/s².
Learn more about acceleration due to gravity at: https://brainly.com/question/11873969
A 4.0 kg mess kit sliding on a frictionless surface explodes into two 2.0 kg parts: 3.0 m/s, due north, and 5.0 m/s, 30° north of east.What is the original speed of the mess kit?
Answer:
3.49m/s
Explanation:
We have mess of kit = 4kg
Then pieces are 2kg
3m/s due north
5m/s, 30⁰ due south
MiVi = m1v1 + m2v2
We break velocities to have x and y components
MiVi = m1v1(cosθ+sin θ1j) + m2v2(v2cos θ2i+sin2 θj)
θ1 = 90⁰north
θ2 = 30⁰ north east
Vi = 2/4x3m/s(cos90i + sin90j)+2/4x5m/s(cos30i + sin30j)
= 2.16i + 2.75j
Vi = √Vx²+Vy²
Vi = √ (2.16)²+(2.75)²
Vi = 3.49m/s
This is the original speed of the kit