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2 years ago

A book on a 2-meter high shelf has a mass of 0.4 kg. What is its potential energy?

Physics

2 answers:

poizon [28]2 years ago

6 0

Answer:

$\boxed {\boxed {\sf 7.84 \ Joules}}$

Explanation:

The formula for potential energy is:

$PE=m*g*h$

where m is the mass, g is the gravitational acceleration, and h is the height.

The mass of the book is 0.4 kilograms. The gravitational acceleration on Earth is 9.8 m/s². The height of the book is 2 meters.

$m=0.4 \ kg \\g=9.8 \ m/s^2 \\h=2\ m$

Substitute the values into the formula.

$PE=(0.4 \ kg)(9.8 \ m/s^2)(2 \ m)$

Multiply the first two numbers.

0.4 kg*9.8 m/s²= 3.92 kg*m/s²
If we convert the units now, the problem will be much easier later on.
1 kg*m/s² is equal to 1 Newton. So, our answer of 3.92 kg*m/s² is equal to 3.92 N

$PE=(3.92 \ N )(2 \ m)$

Multiply.

3.92 N* 2 m=7.84 N*m
1 Newton meter is equal to 1 Joule (this is why we converted the units).
Our answer is equal to 7.84 Joules.

$PE=7.84 \ J$

Aliun [14]2 years ago

4 0

Answer:

7.84 is your answer ok bye

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the specific volumes are:

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Then, the specific work can be written as:

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The fact that the work is negative, means that we need to apply work to the air in order to compress it.

Now, to write it in more common units we have that:

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An electron starts from rest in a vacuum, in a region of strong electric field. The electron moves through a potential differenc

Semenov [28]

Answer:

The kinetic energy is $KE = 5.67*10^{-18} \ J$

Explanation:

From the question we are told that

The potential difference is $\Delta V = 36 \ volts$

The potential energy of the end is mathematically represented as

$PEs = - q * \Delta V$

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substituting values

$PE = - 1.60*10^{-19} * 36$

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The $PE_e = KEe$

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The negative sign is not includes because kinetic energy can not be negative

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