Answer:
20g
Explanation:
Given parameters:
Quantity of heat = 240calories
Initial temperature = 80°C
Final temperature = 68°C
Unknown:
Mass of water = ?
Solution;
To solve this problem, we use the expression:
Q = m c (t₂ - t₁)
Q is the quantity of heat
m is the mass
c is the specific heat = 1 cal/g°C
t₂ is the final temperature
t₁ is the initial temperature
Insert the parameters and solve;
Change in temperature is an absolute value
240 = m x 1 x (68 - 80)
m = 20g
Deshaun Watson launches a football at a speed of 24.7 ms and an angle of 33° above the horizontal How far down
the football field does the football land? What is the max height the football reaches during flight?
Show work
Answer:
9.23m
Explanation:
Max height = u²sin²theta/2g
u is the speed = 34.7m/s
theta is the angle of elevation = 33°
g is the acceleration due to gravity = 9.8m/s²
Substitute into the formula
Max height = 24.7²sin²33/2(9.8)
Max height = 610.09sin²33/2(9.8)
Max height = 610.09(0.29663)/19.6
Max height = 180.97/19.6
Max Height = 9.23m
Hence the max height the football reaches during flight is 9.23m
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.
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%
WILL GIVE BRAINLIEST TO THE CORRECT ANSWER
PLEASE HELP THIS IS DUE TODAY!
If a 1000kg car is accelerating at 3m/s/s for 4 seconds how far will it travel
( I will give a brainliest )
What must be changed, temperature or heat energy, during condensation?
Answer:
The answer is temperature lol
Explanation:
:)
Select the correct answer.
Which of these factors will increase the speed of a sound wave in the air?
A. slowing down the movement of particles in the air
B. raising the temperature of the air
C. removing particles form the air
D. decreasing the kinetic energy of the air
E. stopping particle collisions in the air
Answer:
B
Explanation:
But molecules at a higher temperature have more energy.
Answer: B. Raising the temperature of the air
If the angle between two forces increases, the magnitude of their resultant-
A Decreases
C. Remain unchanged
D. Decrease than decreases
How will a metal container full of hot water in vaccum lose heat?
A satellite of mass m orbits a moon of mass M in uniform circular motion with a constant tangential speed of v. The gravitational field strength at a distance R from the center of moon is gR. The satellite is moved to a new circular orbit that is 2R from the center of the moon. What is the gravitational field strength of the moon at this new distance
The satellite is moved to a new circular orbit that is 2R from the center of the moon, then the gravitational field strength of the moon at this new distance would be one-fourth of the initial gravitational field.
What is gravity?It can be defined as the force by which a body attracts another body toward its center as the result of the gravitational pull of one body and another.
As given in the problem A satellite of mass m orbits a moon of mass M in a uniform circular motion with a constant tangential speed of v. The gravitational field strength at a distance R from the center of the moon is gR. The satellite is moved to a new circular orbit that is 2R from the center of the moon.
The gravitational field strength is inversely proportional to the square of the distance from the center of the planet.
Thus, the gravitational field strength of the moon at this new distance would be one-fourth of the initial gravitational field.
To learn more about gravity here, refer to the link given below ;
brainly.com/question/4014727
#SPJ1
A particular inductor is connected to a circuit where it experiences a change in current of 0.8 amps every 0.10 sec. If the inductor has a self-inductance of 2.0 V, what is the inductance
Answer:
0.4
Explanation:
Given that a particular inductor is connected to a circuit where it experiences a change in current of 0.8 amps every 0.10 sec. If the inductor has a self-inductance of 2.0 V, what is the inductance
Using the power formula
P = IV
Substitute all the parameters
P = 0.8 × 2
P = 1.6 W
But P = I^2 R
Substitute power and current
1.6 = 0.8^2 R
R = 1.6 / 0.64
R = 2.5 ohms
Inductance = reciprocal of resistance
Inductance = 1 / 2.5
Inductance = 0.4
What is the current in a 160V circuit if the resistance is 200?
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
Please leave a like if it helped you
The plate area is doubled, and the plate separation is reduced to half its initial separation. What is the new charge on the negative plate
Answer:
Q = 4 Q₀
Explanation:
This is an exercise on capacitors, where the capacitance is
C = [tex]\epsilon_{o} \ \frac{A}{d}[/tex]
if we apply the given conditions
C = \epsilon_{o} \ \frac{2A}{0.5d}
C = 4 \epsilon_{o} \ \frac{A}{d}
let's call the capacitance Co with the initial values
C₀ = \epsilon_{o} \ \frac{A}{d}
C = 4 C₀
The charge on each plate of a capacitor is
Q = C ΔV
If the potential difference is maintained, the new charge is
Q = 4 C₀ ΔV
let's call
Q₀ = C₀ ΔV
we substitute
Q = 4 Q₀
What are your thoughts about Russia getting banned from the 2020 Olympics and 2022 World cup?
1. A low frequency will have a wavelength?
Answer:
There are many kinds of waves all around us. There are waves in the ocean and in lakes. Did you also know that there are also waves in the air? Sound travels through the air in waves and light is made up of waves of electromagnetic energy.
The wavelength of a wave describes how long the wave is. The distance from the "crest" (top) of one wave to the crest of the next wave is the wavelength. Alternately, we can measure from the "trough" (bottom) of one wave to the trough of the next wave and get the same value for the wavelength.
The frequency of a wave is inversely proportional to its wavelength. That means that waves with a high frequency have a short wavelength, while waves with a low frequency have a longer wavelength.
Light waves have very, very short wavelengths. Red light waves have wavelengths around 700 nanometers (nm), while blue and purple light have even shorter waves with wavelengths around 400 or 500 nm. Some radio waves, another type of electromagnetic radiation, have much longer waves than light, with wavelengths ranging from millimeters to kilometers.
Sound waves traveling through air have wavelengths from millimeters to meters. Low-pitch bass notes that humans can barely hear have huge wavelengths around 17 meters and frequencies around 20 hertz (Hz). Extremely high-pitched sounds that are on the other edge of the range that humans can hear have smaller wavelengths around 17 mm and frequencies around 20 kHz (kilohertz, or thousands of Hertz).
Explanation:
Explanation:
Hope This Helped U
Brqinliest
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
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
An inductor with an inductance of .5 henrys (H) is to be connected to a 60 Hz circuit. What will the inductive reactance (X L) be
Answer:
1885.2 ohms
Explanation:
Step one:
given data
L=5H
f=60Hz
Required
The inductive reactance of the inductor
Step two:
Applying the expression
XL= 2πfL
substitute
XL=2*3.142*60*5
XL=1885.2 ohms
What is constant of a spring if there is 150 j when stretched 0.25 m?
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
Two hockey pucks with mass 0.1 kg slide across the ice and collide. Before
the collision, puck 1 is going 15 m/s to the east and puck 2 is going 12 m/s to
the west. After the collision, puck 2 is going 15 m/s to the east. What is the
velocity of puck 1?
Answer:
Puck 1 = 12 m/s
Explanation:
Conservation of energy
KE_1a + KE_2a = KE_1b + KE_2b
(1/2)(0.1kg)(15m/s)^2 + (1/2)(0.1kg)(12m/s)^2 = (1/2)(0.1kg)(V)^2 + (1/2)(0.1kg)(15m/s)^2
V = 12m/s
Answer:
12 m/s west
Explanation:
just did it
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
Which type of telescope is best used to detect distant planets?
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.
Learn more about refection at: https://brainly.com/question/15487308
#SPJ2
What is the relationship between force and momentum?
A. A force will always increase momentum
B. A force acting for a certain time results in a change in momentum
C. There is no relationship
D. It depends on the kind of force
Answer:
Explanation:
B
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.
Help! Help!
___ 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.
Learn more about drinking and driving.
https://brainly.com/question/11317786
#SPJ2
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
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.
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