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2 years ago

A man lifts a 120 kg barbell 2 m above the ground . What is the gain in gravitational PE of the barbell?

Physics

1 answer:

SpyIntel [72]2 years ago

7 0

Answer:

2,352 Joules

Explanation:

At the ground, the barbell has a classical mechanical energy value of zero. There is no classical kinetic or potential energy for the barbell. The moment the man starts to lift the barbell, he does work on the barbell and transfers kinetic energy to it due to the motion. At its maximum height where the man lifts the barbell to a stop, the kinetic energy is zero because it transformed into gravitational potential energy stored in the gravitational field. Our reference point for potential was defined to be zero at the floor, therefore we can say that the gravitational potential energy at 2 meters is:

$U=mgh=(120kg)(9.8m/s^2)(2m)=2,352J$

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Distance in scientific notation

n200080 [17]

Answer:

(See explanation for further information)

Explanation:

a) The distances of each planet with respect to the Sun is:

Mercury - $57.909 \times 10^{6}\,mi$

Venus - $67.240\times 10^{6}\,mi$

Earth - $92.960\times 10^{6}\,mi$

Mars - $141.600\times 10^{6}\,mi$

Jupiter - $483.800\times 10^{6}\,mi$

Saturn - $888.200\times 10^{6}\,mi$

Uranus - $1,787\times 10^{6}\,mi$

Neptune - $2,795\times 10^{6}\,mi$

b) The solutions are presented below:

A. The distance between Venus and Jupiter is:

$\Delta s = 483.800\times 10^{6}\,mi-67.240\times 10^{6}\,mi$

$\Delta s = 416.560\times 10^{6}\,mi$

B. The combined distance from the Sun is:

$\Delta s = 57.909\times 10^{6}\,mi + 67.240\times 10^{6}\,mi +92.960\times 10^{6}\,mi$

$\Delta s = 218.109\times 10^{6}\,mi$

Which is less than the distance from the Sun to Neptune ( $2,795\times 10^{6}\,mi$ ).

C. The new distance of Earth is $929.60 \times 10^{6}\,mi$ ( $929,600,000\,mi$ ). Saturn would be the closest planet to Earth, whose distance:

Scientific notation:

$\Delta s = 929.600\times 10^{6}\,mi-888.200\,\times 10^{6}\,mi$

$\Delta s = 41.4\times 10^{6}\,mi$

Standard notation:

$\Delta s = 929,600,000\,mi - 888,200,000\,mi$

$\Delta s = 41,400.000\,mi$

3 0

4 years ago

When you put your hands on a cold object like a glass of ice water your hands become?

nikklg [1K]

Your hand will be cold.
if you do it often enough, you will realize your fingernails will not grow as fast (Fun fact)

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3 years ago

A particle undergoes a displacement δr⃗ of magnitude 54 m in a direction 42 ∘ below the x axis.

Elina [12.6K]

Please elaborate more on your question so I can help you

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3 years ago

Worldâs tallest building. suppose that you drop a marble from the top of the burj khalifa building in dubai, which is about 830

-Dominant- [34]

a) 13 seconds b) 130 m/s The formula for the distance an object moves while under constant acceleration is d = 1/2AT^2. So let's define d as 830 m, A as 9.8m/s^2, and solve for T 830 m = 1/2 9.8 m/s^2 T^2 830 m = 4.9 m/s^2 T^2 Divide both sides by 4.9 m/s^2 169.3878 s^2 = T^2 Take the square root of both sides 13.01491 s = T Since we only have 2 significant figures, round the result to 13 seconds which is the answer to the first part of the question. To find out how fast the marble is moving, just multiply T and A together 13 s * 9.8 m/s^2 = 127.4 m/s Since we only have 2 significant figures, round the result to 130 m/s.

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4 years ago

Which of the following is a physical property of water?

photoshop1234 [79]

Hi there!

First of all, you have to pay attention to the question, and they are asking for something physical, and physical means to be seen on the outside.

The answer is A because you can clearly see that water is a liquid. Being a liquid is a physical property.

It wouldn't be B because I believe it would be a chemical property to react with many substances.

Hope this helps! :D

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3 years ago

Read 2 more answers