two cars with initial speed 2v and v, lock their brakes and skid to a stop. what is the ratio of the distance travelled
Answer:
4:1
Explanation:
Given that the initial speed of the first car, u = 2v while the initial speed of the second car, u = v. To find the distance travelled, we are going to apply one of the equations of motion. The equation chosen is
v² = u² - 2as, where
s = the distance needed
a = acceleration due to gravity
u = initial velocity which is v & 2v
v = final velocity which is 0
For the first car with initial velocity, 2v, on substituting into the equation, we have
v² = u² - 2as(1)
0 = 4v - 2as(1)
4v = 2as(1)
2v = as(1), making s(1) subject of formula we have
s(1) = 2v/a
Taking the second car, we have u = v
v² = u² - 2as(2)
0 = v - 2as(2)
v = 2as(2), making s(2) subject of formula, we have
s(2) = v/2a
Not, ratio of s1 : s2 =
2v/a : v/2a
s1/s2 = 2v/a ÷ v/2a
s1/s2 = 2v/a * 2a/v
s1/s2 = 4av/av
s1/s2 = 4/1
Therefore, the ratio of the first car to the second car is 4:1
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___ are a primary way to discourage drinking and driving.
A. High prices for alcohol
B. Scare tactics
C. Laws
Answer:
Laws
Explanation:
Laws are a primary way discourage drinking and driving
A primary way to discourage drinking and driving is Law.
What is drinking and driving?The person who takes in alcohol and then drives on the road. This is strictly prohibited.
Laws against the 'drinking and driving' will make people get scared of getting charged or sentenced to jail for some years. Lot of accidents have caused when there were no laws against the action.
Thus, Laws are a primary way to discourage drinking and driving.
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Two identical plastic cups contain the same amount of water at two different temperatures, as shown to the left. Both cups are placed in a room at 25° Celsius. At the time cups were placed in the room, in which cup do the water molecules have higher average kinetic energy? ( Cup 1 © Cup 2
Answer:
the molecules will begin to move slowly and will turn to ice
Explanation:
hope this was good or not not sure if am right but yeah
let's say you hypothetically ran over someone with your car, and they are now under your car in between the front wheels and the back wheels, right, and they're stuck as in can't breathe type stuck, right, do you keep driving so they can breathe or do you let them chill under your car?
just curious...
question: is this actually hypothetical?
Explanation:
also just leave the car there go get some McDonald's or sum and come back and if they're still breathing then go ahead and move the car .
Answer:
the same thing the last guy said
Optimus Prime is flying straight up at 24 m/s when he accidentally drops his mega-ray blaster and it falls 94 m to the ground below. Calculate how long it takes for his mega-ray blaster to hit the ground.
Answer:
The time it will take the mega-ray blaster to hit the ground is 2.57 s.
Explanation:
Given;
initial velocity of Optimus Prime, u = 24 m/s
height of fall of the mega-ray blaster, h = 94 m
The time of fall of the mega-ray blaster is calculated using the following kinematic equation;
[tex]h = ut + \frac{1}{2}gt^2\\\\94 = 24t + \frac{1}{2}(9.8)t^2\\\\94 = 24t + 4.9t^2\\\\4.9t^2 +24t -94 = 0\\\\Use \ formula \ method \ to \ solve \ for \ "t"\\\\a = 4.9 , b = 24, c = -94\\\\t = \frac{-b \ +/- \ \sqrt{b^2 -4ac} }{2a} \\\\t = \frac{-24 \ +/- \ \sqrt{(24)^2 -4(-94 \times4.9)} }{2(4.9)} \\\\t = \frac{-24 \ +/- \ \sqrt{2418.4} }{9.8}\\\\t = \frac{-24 \ +/- \ 49.177 }{9.8}\\\\t = \frac{-24 \ +\ 49.177 }{9.8} \ \ or \ \ t = \frac{-24 \ -\ 49.177 }{9.8} \\\\[/tex]
[tex]t = 2.57 \ s \ \ or \ \ t = -7.47 \ s[/tex]
t = 2.57 s
Therefore, the time it will take the mega-ray blaster to hit the ground is 2.57 s.
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What must be changed, temperature or heat energy, during condensation?
Answer:
The answer is temperature lol
Explanation:
:)
The metal wire is stretched so that its cross-section is still circular but its total length is now 10 meters. What is the resistance of the wire after stretching
A 420 g soccer ball is kicked into the air with an initial velocity of 30 m/s. How much kinetic energy does the soccer ball have?
Answer:189000J
Explanation:KE=1/2mv^2
1/2(420g)(30m/s)^2
=189000J
A volleyball experiences 494 Ns of impulse over a time period of 7 seconds. What was the magnitude of the force that acted on the volleyball during this time period?
Answer:
70.6N
Explanation:
Given parameters:
Impulse = 494Ns
Time = 7s
Unknown:
Force applied = ?
Solution:
To solve this problem, we use the formula of impulse;
Impulse = Force x time
Now insert the parameters and solve;
494 = Force x 7
Force = [tex]\frac{494}{7}[/tex]
Force = 70.6N
4) Which of the following is NOT true about lysozyme:
A) it destroys bacteria
B) it cleanses and protects the eye
C) it is an enzyme
D) it is found in tears
E) it stimulates the rods and cones
Select the correct answer.
What type of motion means to bounce or spring back?
Spin
Rotate
Rebound
Speed
Answer:
Rebound
Explanation:
Answer:
Rebound is your answer
Explanation:
To rebound is to bounce or
spring back after coming into
contact with another object.
Examples:
Rebound
• A basketball rebounds off the
backboard.
• A hockey puck rebounds off
the wall.
The least count of stopwatch is 0.2s.The time of 20 oscillations of a pendulum was measured to be 25s.Find the percentage error in the measurement of time
Answer:
0.8%
Explanation:
We are given;
Number of oscillations; n = 20
Time taken; t = 25 s
Formula for period of oscillation;
T = t/n = 25/20 = 1.25 s
We are told that the least count is 0.2 s. Thus, error is; ΔT = 0.2 s
percentage error in the measurement of time is given by;
(0.2/(20 × 1.25)) × 100% = 0.8%
please help thank you
which of the following statements BEST describes the difference between an atom and an ion ?
Answer:
well the correct answer is
d. An atom contains equal numbers of protons and electrons whereas an ion contains unequal numbers of protons and electrons .Explanation:
A charged atom is known as an ion, well it can be negative as well as positive charge.
if atom has more protons than electrons then it get positively charged and known as cationif the atom has more electrons that the number of protons then the atom get negatively charged and known as anionAn automobile which set the world record for acceleration increase speed from rest to 96 km/h in 3.07 seconds what distance traveled by the time the final speed was achieved
Answer:
41.02m
Explanation:
Given parameters:
Initial velocity = 0m/s
Final velocity = 96km/hr
Time taken = 3.07s
Unknown:
Distance traveled by the time the final speed was achieved = ?
Solution:
To solve this problem, we first find the acceleration of the car;
Acceleration = [tex]\frac{v - u }{t}[/tex]
v is the final velocity
u is the initial velocity
t is the time taken
Now convert the the final velocity to m/s;
96km/hr to m/s;
1 km/hr = 0.278m/s
96km/hr = 96 x 0.278 = 26.7m/s
Now;
Acceleration = [tex]\frac{26.7 - 0}{3.07}[/tex] = 8.69m/s²
So;
v² = u² + 2as
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance
26.7² = 0² + 2 x 8.69 x s
712.89 = 17.38s
s = 41.02m
What happens to most of the light waves that strike a clear pane of glass? O A. absorption B. diffraction O C. reflection O D. transmission
slight reflect but most goes through because glass is transparent
Most of the light waves that strike a clear pane of glass reflects. Details about reflection can be found below.
What is reflection?Refection in physics is the property of a propagated wave being thrown back from a surface such as a mirror.
Mirror is an example of an object that could be hit by an incumbent wave, however, most of the light waves that hit the mirror surface gets reflected back.
Therefore, most of the light waves that strike a clear pane of glass reflects.
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1. A 75.0 kg man pushes on a 500,000kg wall for 250s but it does not move. How
much work does he do on the wall?
Answer:
0J
Explanation:
No work is being done on the wall by the man pushing on it.
Given parameters:
Mass of man = 75kg
Mass of wall = 500000kg
Time = 250s
Unknown:
Work done = ?
Solution:
Work done is the force applied on a body that moves it along a particular path.
For work to be done, distance must be move or displacement must occur.
Since the wall is not moving the distance is 0;
Work done = Force x distance
Since distance is 0m, work done is 0J
The work done on the wall by the man is 0 J.
To calculate the amount of work done by the man, we use the formula below.
Formula:
W = (ma)d............. Equation 1Where:
W = Work done on the wall by the manm = mass of the walla = acceleration of the walld = distance.from the question,
Given:
m = 500000 kga = 0 m/s² (not moving)d = 0 m.Substitute these values into equation 1
W = 500000(0)(0)W = 0 J.Hence, the work done on the wall by the man is 0 J.
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A different bullet has a mass of 0.09 kg. Starting from rest, after its gun's trigger is pulled, a constant force acts on the bullet for the next 0.025 seconds until the bullet leaves the barrel of the gun with a speed of 1,346 m/s.
What force acts on this bullet?
The force acts on this bullet : 4.8456 N
Further explanationGiven
m=0.09 kg
Δt=0.025 s
vo=0(from rest)
vt=1.346 m/s
Required
Force
Solution
Impulse is a change in momentum
I=ΔP
F.Δt=m(vt-vo)
Input the value
F x 0.025 = 0.09(1.346-0)
F=4.8456 N
A(n) 636 kg elevator starts from rest. It moves upward for 4.5 s with a constant acceleration until it reaches its cruising speed of 2.05 m/s. The acceleration of gravity is 9.8 m/s 2 . Find the average power delivered by the elevator motor during this period. Answer in units of kW.
Answer:
The average power delivered by the elevator motor during this period is 6.686 kW.
Explanation:
Given;
mass of the elevator, m = 636 kg
initial speed of the elevator, u = 0
time of motion, t = 4.5 s
final speed of the elevator, v = 2.05 m/s
The upward force of the elevator is calculated as;
F = m(a + g)
where;
m is mass of the elevator
a is the constant acceleration of the elevator
g is acceleration due to gravity = 9.8 m/s²
[tex]a = \frac{v-u}{t} \\\\a = \frac{2.05 -0}{4.5} \\\\a = 0.456 \ m/s^2[/tex]
F = (636)(0.456 + 9.8)
F = (636)(10.256)
F = 6522.816 N
The average power delivered by the elevator is calculated as;
[tex]P_{avg} = \frac{1}{2} (Fv)\\\\P_{avg} = \frac{1}{2} (6522.816 \ \times \ 2.05)\\\\P_{avg} = 6685.89 \ W\\\\P_{avg} = 6.68589 \ kW\\\\P_{avg} = 6.686 \ k W[/tex]
Therefore, the average power delivered by the elevator motor during this period is 6.686 kW.
how are hydrosphere, atmosphere, Biosphere, and Biosphere connected to one another
Explanation:
Such spheres are intimately connected. Many animals (biosphere), for example, migrate through to the sky, while groundwater (hydrosphere) also flows through the ground (lithosphere). The domains are actually so closely related that a shift in one globe always results in a shift in one or both of some other spheres.
which of the following is not a mechanical form of energy?
a. Nuclear
b. Kinetic
c. Spring potential
d. Gravitational potential
Answer:
The answer is Spring Potential
Explanation:
Because all the others are a mechanical form of energy
Q2. You push a crate up a ramp with a force of 10 N. Despite your pushing, the crate slides down the ramp 4 m. How much work did you do
Answer:
40 J
Explanation:
From the question given above, the following data were obtained:
Force (F) = 10 N
Distance (s) = 4 m
Workdone (Wd) =?
Work done is simply defined as the product of force and distance moved in the direction of the force. Mathematically, we can express the Workdone as:
Workdone = force × distance
Wd = F × s
With the above formula, we can obtain the workdone as follow:
Force (F) = 10 N
Distance (s) = 4 m
Workdone (Wd) =?
Wd = F × s
Wd = 10 × 4
Wd = 40 J
Thus, 40 J of work was done.
a ball of diameter 10 cm and mass 10 grams is dropped in a container of water. the cross sectional area of the container is 100 cm2.. what is the change in the height of the water column
Answer:
h = 9.83 cm
Explanation:
Let's analyze this interesting exercise a bit, let's start by comparing the density of the ball with that of water
let's reduce the magnitudes to the SI system
r = 10 cm = 0.10 m
m = 10 g = 0.010 kg
A = 100 cm² = 0.01 m²
the definition of density is
ρ = m / V
the volume of a sphere
V = [tex]\frac{4}{3} \ \pi r^{3}[/tex]
V = [tex]\frac{4}{3}[/tex] π 0.1³
V = 4.189 10⁻³ m³
let's calculate the density of the ball
ρ = [tex]\frac{0.010}{4.189 \ 10^{-3} }[/tex]
ρ = 2.387 kg / m³
the tabulated density of water is
ρ_water = 997 kg / m³
we can see that the density of the body is less than the density of water. Consequently the body floats in the water, therefore the water level that rises corresponds to the submerged part of the body. Let's write the equilibrium equation
B - W = 0
B = W
where B is the thrust that is given by Archimedes' principle
ρ_liquid g V_submerged = m g
V_submerged = m / ρ_liquid
we calculate
V _submerged = 0.10 9.8 / 997
V_submerged = 9.83 10⁻⁴ m³
The volume increassed of the water container
V = A h
h = V / A
let's calculate
h = 9.83 10⁻⁴ / 0.01
h = 0.0983 m
this is equal to h = 9.83 cm
If at some point in time an object has zero velocity and zero acceleration, what does that mean about its motion at the next instant
Answer:
Explanation:
Usually, when an object possesses 0 velocity, then the object is expected to be at rest. But like the popular saying, there's always an exception to every rule. There exists cases in which an object isn't at rest, but possesses 0 speed or velocity. Since acceleration is the rate of change of velocity with time, the acceleration becomes negative, instead of positive.
Again, when the acceleration becomes zero, it means that the object isn't moving or it has no speed. And thus, the body is at rest. Every moving body as an acceleration, either positive, or negative. Zero acceleration means the object is at rest, and not moving at all.
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At any point in time, when
when the acceleration becomes zero, it means that the object isn't moving or it has no speed. And thus, the body is at rest.
What is acceleration?Acceleration is defined as the change of the velocity with the time. Acceleration is a vector quantity and is defined by both the magnitude and the direction
when the acceleration becomes zero, it means that the object isn't moving or it has no speed. And thus, the body is at rest. Every moving body as an acceleration, either positive, or negative. Zero acceleration means the object is at rest, and not moving at all.
Now If an object is moving with an acceleration that causes its speed to be reduced, there will be a moment in which it reaches v = 0, but this doesn't necessarily mean that the acceleration isn't acting anymore. If the object continues its movement with the same acceleration, it's velocity will become negative.
If you throw an object in the air with a certain velocity, it will move vertically, reducing its velocity in a 9,8 rate (which is the acceleration caused by gravity). At a certain point, the object will reach its maximum height, and will start to fall. In the exact moment that it reaches the maximum height, before it starts falling, its velocity is zero, but gravity is still acting on the object (this is the reason why it starts falling instead of just being stopped at that point). Therefore, at that point, the object has zero velocity but an acceleration of 9,8 .
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Question 3 (1 point)
here were 2cars racing a quarter mile. The green car had a mass of 1200kg and crossed the finish line with a velocity of 53m/s. The red car had
a mass of 1100Kg and crossed the finish line with a velocity of 55m/s.,Which car had the great momentum?
Black car
Blue car
Green car
Red car
Answer:
The green car had the greatest momentum
Explanation:
Momentum
Momentum can be defined as "mass in motion" and is calculated as the product of the mass of the object by its velocity.
Being v the magnitude of the velocity and m the mass of the object, the momentum is calculated with:
p = mv
The green car had a mass of m1=1200 kg and crossed the finish line at v1=53 m/s. Hence, its momentum was:
p1 = 1200 Kg * 53 m/s = 63600 Kg.m/s
The red car had a mass of m2=1100 kg and crossed the finish line at v2=55 m/s. Hence, its momentum was:
p2 = 1100 Kg * 55 m/s = 60500 Kg.m/s
Since p1 > p2, then the green car had the greatest momentum
14. After finishing her homework, Sue climbs up a 5.00 m high flight of stairs to her bedroom
Find the magnitude of Sue's weight
and how much
work Sue does in climbing the stairs if she
has a mass of 50.0 kg? (4.90 x 2 N, 2450J)
Explanation:
Given parameters:
Height = 5m
Mass of Sue = 50kg
Unknown:
Magnitude of Sue's weight = ?
Work done by Sue = ?
Solution:
Weight is the vertical force exerted by a body in the presence of gravity.
Mathematically;
W = mg
m is the mass
g is the acceleration due to gravity = 9.8m/s²
Weight = 50 x 9.8 = 490N
Work done = Force x distance = weight x height
Work done = 490 x 5 = 2450J
Define friction. Prove that tangent of angle of friction is equal to coefficient
of friction.
Answer:
Friction is the force that opposes movement between moving objects.
The angle at which one object starts to slip on the other is directly related to the coefficient. When the two objects are horizontal there is no frictional force. So, the coefficient of static friction is equal to the tangent of the angle at which the objects slide. A similar method can be used to measure μk.
Explanation:
Answer:
brainliest plsssssss
Explanation:
The resistance that one surface or object encounters when moving over another
Determine the absolute pressure on the bottom of a swimming pool 30.0 mm by 8.4 mm whose uniform depth is 1.9 mm .
Answer:
=101343.62N/m^2
Explanation:
absolute pressure on the bottom of a swimming pool= atmospheric pressure +( 2 ×ρ ×g)
( 2 ×ρ ×g)= guage pressure
atmospheric pressure= 101325pa
h= height= 1.9 mm = 1.9×10^-3m
ρ = density of water
= 1000kg/m^3
g= acceleration due to gravity= 9.8m/s^2
Then substitute, we have
absolute pressure on the bottom of a swimming pool= 101325+ [0.0019 ×1000 × 9.8)]
=101343.62N/m^2
Hence, the absolute pressure on the bottom of a swimming pool is =101343.62N/m^2