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3 years ago

Work can _____ energy between objects and can cause a change in the form of energy.

Physics

1 answer:

zhuklara [117]3 years ago

6 0

Answer:

Work can transfer energy between objects and can cause a change in the form of energy.

Explanation:

The best explanation can be done with an example.Consider an apple of mass m falling from a tree. Initially, the apple is at rest on the tree, at a certain height h above the ground, so it has a form of energy called gravitational potential energy, equal to: where g is the acceleration due to gravity.As the apple falls, the force of gravity acts on it, and so this force does work on the apple. As a result, the potential energy of the apple is converted into another form of energy, kinetic energy, which is the energy due to the motion of the apple: where v is the speed of the apple.Consider another example: a man pushing a box along the floor with a force F. The man is doing work on the box, and this work is equal towhere d is the displacement of the box. As a result of this work, some of the chemical energy contained in the muscles of the man is transferred into the box and converted to kinetic energy of the box, which is put in motion and it gains a certain speed v. In particular, if there are no frictional forces involved, the work done by the man is equal to the kinetic energy gained by the box.

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Which object will have the greatest change in

Brut [27]

(4) a metal sphere with a charge of 1.0 × 10^−9 C moved through a potential difference of 4.0 V would undergo the greatest change in electrical energy from the list.

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3 years ago

A ball is thrown down vertically with an initial speed of 20 m/s from a height of 60 m. Find (a) its speed just before it strike

vivado [14]

Answer:

Explanation:

Ball is thrown downward:

initial velocity, u = - 20 m/s (downward)

height, h = - 60 m

Acceleration due to gravity, g = - 9.8 m/s^2 (downward)

(a) Let the speed of the ball as it hits the ground is v.

Use third equation of motion

$v^{2}=u^{2}+2as$

$v^{2}=(-20)^{2}+2\times 9.8 \times 60$

v = 39.69 m/s

(b) Let t be the time taken

Use First equation of motion

v = u + a t

- 39.69 = - 20 - 9.8 t

t = 2 second

Now the ball is thrown upwards:

initial velocity, u = 20 m/s (upward)

height, h = - 60 m

Acceleration due to gravity, g = - 9.8 m/s^2 (downward)

Use third equation of motion

$v^{2}=u^{2}+2as$

$v^{2}=(-20)^{2}+2\times 9.8 \times 60$

v = 39.69 m/s

(d) Let t be the time taken

Use First equation of motion

v = u + a t

- 39.69 = + 20 - 9.8 t

t = 6.09 second

3 0

2 years ago

What is the gravitational field strength of a 5 kg object that weighs 25 N?

solniwko [45]

Answer:

ExplanaThis is a way of measuring how much gravity there is. The formula is: weight/mass = gravitational field strength.

Gravitational field strength = Weight/mass unit is N/kg

Weight = mass x gravitational field strength unit is N

On Earth the gravitational field strength is 10 N/kg. Other planets have different gravitational field strengths. The Moon has a gravitational field strength of 1.6 N/kg. You might have seen films of astronauts leaping high on the moon.

Here on Earth, if I jump I am pulled back to ground by gravity. What is my weight? My mass is 80kg and if we multiply by gravitational field strength (10N/kg) - my weight is 800N. Now if I go to the moon, my mass will be the same, 80kg. We multiply that by the moon's gravitational field strength, which is 1.6 N/ kg. That means my weight on the moon is 128N. So I have different weights on the Earth and on the Moon. That's why astronauts can jump high into the air on the moon - they're lighter up there.

Jupiter is a very large planet with strong gravitational field strength of 25 N/ kg. My body is 80kg. If I go to Jupiter my weight is going to be 25 x 80 = 2,000 N. That means I wouldn't be able to get off the ground or stand up straight! I would probably be lying down all the time there. So weight varies depending on which planet you are on. You can find out more yourself by looking up tables of weight on different planets.tion:

pls brainlieste

7 0

2 years ago

Read 2 more answers

a sprinter with a mass of 80kg accelerates uniformly from 0 m/s to 9 m/s in 3 s. a.)what is the runners acceleration? b.) what i

Katyanochek1 [597]

Part A:
Acceleration can be calculated by dividing the difference of the initial and final velocities by the given time. That is,
a = (Vf - Vi) / t
where a is acceleration,
Vf is final velocity,
Vi is initial velocity, and
t is time

Substituting,
a = (9 m/s - 0 m/s) / 3 s = 3 m/s²
ANSWER: 3 m/s²

Part B:
From Newton's second law of motion, the net force is equal to the product of the mass and acceleration,
F = m x a
where F is force,
m is mass, and
a is acceleration

Substituting,
F = (80 kg) x (3 m/s²) = 240 kg m/s² = 240 N

ANSWER: 240 N 

Part C:
The distance that the sprinter travel is calculated through the equation,
d = V₀t + 0.5at²

Substituting,
d = (0 m/s)(3 s) + 0.5(3 m/s²)(3 s)²
d = 13.5 m

ANSWER: d = 13.5 m

3 0

2 years ago

Help me please i dont understand

solniwko [45]

Answer:

It is b

Explanation:

The question tells you that the distance was increased 3 times the original distance, which means it was moved 3 times

5 0

3 years ago