Question

A salmon jumps 2.0 m vertically and gains a certain amount of potential energy. A second salmon of half the mass jumps the same vertical height. Compared to the first salmon, the second salmon’s potential energy gain is?
a. one-half as great b. twice as great c. the same d. 4 times as great

Answer 1

Answer:

a. one-half as great

Explanation:

Potential energy is the energy at rest of a body.

To solve this problem,

      Potential energy  = mgh

where m = mass

           g = acceleration due to gravity

           h = height

 Now;

  Salmon 1;                                  Salmon 2;

       mass  = m                             mass = $\frac{m}{2}$

       g  = 9.8m/s²                           g = 9.8m/s²    

        h = 2m                                   h = 2m

Now,

Potential energy of salmon 1 = m x 9.8 x 2 = 19.6m

Potential energy of salmon 2 =  $\frac{m}{2}$ x 9.8 x = 9.8m

  Comparing the two potential energy values;

 Salmon 1                Salmon 2

    19.6m                      9.8m

  We see that the potential energy of salmon 1 is twice that of salmon 2.

  The potential energy of salmon 2 is half that of salmon 1