Question

A dolphin experiences a force of 320 N [U] when it jumps out of the water. The acceleration of the dolphin is 2.60 m/s2 [U]. a) Calculate the mass of the dolphin. b) What would be the acceleration of the dolphin if it had the same strength but half the mass?

Answer 1

a) The mass of the dolphin can be calculated by using Newton's second law:

$F=ma$

where

F=320 N is the force experienced by the dolphin

m is the dolphin mass

$a=2.60 m/s^2$ is the acceleration of the dolphin

Rearranging the equation and substituting the numbers, we find the mass of the dolphin:

$m=\frac{F}{a}=\frac{320 N}{2.60 m/s^2}=123.1 kg$

b) If the mass of the dolphin is halved, the new mass is:

$m=\frac{123.1 kg}{2}=61.6 kg$

And by using again Newton's second law, we can find the new acceleration of the dolphin:

$a=\frac{F}{m}=\frac{320 N}{61.6 kg}=5.2 m/s^2$

so, the acceleration is twice the original acceleration.

Answer 2

A) f=ma (solve for a)
b) I think it is 22.5.