a) The mass of the dolphin can be calculated by using Newton's second law:
[tex] F=ma [/tex]
where
F=320 N is the force experienced by the dolphin
m is the dolphin mass
[tex] a=2.60 m/s^2 [/tex] is the acceleration of the dolphin
Rearranging the equation and substituting the numbers, we find the mass of the dolphin:
[tex] m=\frac{F}{a}=\frac{320 N}{2.60 m/s^2}=123.1 kg [/tex]
b) If the mass of the dolphin is halved, the new mass is:
[tex] m=\frac{123.1 kg}{2}=61.6 kg [/tex]
And by using again Newton's second law, we can find the new acceleration of the dolphin:
[tex] a=\frac{F}{m}=\frac{320 N}{61.6 kg}=5.2 m/s^2 [/tex]
so, the acceleration is twice the original acceleration.
