Answer:

Explanation:
When heat energy is supplied to an object, the temperature of the object increases according to the equation:

where
Q is the heat supplied
C is the heat capacity of the object
is the change in temperature
In this problem we have:
is the energy supplied
is the change in temperature of the object
Therefore, the heat capacity of the object is:

To find the impulse you multiply the mass by the change in velocity (impulse=mass×Δvelocity). So in this case, 3 kg × 12 m/s ("12" because the object went from zero m/s to 12 m/s).
The answer is 36 kg m/s
a = 7.8 m/s^2
Explanation:
Let Fnet = net force = ma
m = mass of the skydiver
a = acceleration caused by Fnet
W = weight = mg
f(air) = frictional force due to air resistance
Fnet = W - f(air)
= (100 kg)(9.8 m/s^2) - (200 N)
= 780 N
Therefore, the acceleration of the skydiver due to Fnet is
a = Fnet/m
= (780 N)/(100 kg)
= 7.8 m/s^2