Potential energy decreases and kinetic energy increases.
Potential energy is related to the height, since the wagon is going downhill, height decreases and potential energy decreases.
Kinetic energy is related to the speed, since the wagon is speeding up, kinetic energy increases.
Answer:

Given:
Mass of the polar bear (m) = 6.8 kg
Speed of the polar bear (v) = 5.0 m/s
To Find:
Kinetic energy of the polar bear (KE)
Explanation:
Formula:

Substituting values of m & v in the equation:





Kinetic energy of the polar bear (KE) = 23002.1 J
In my text book for social studies it says a canal
Explanation:
F=m(v-u)/t
F=2N
m=2kg
t=2s
2=2(v-u)/2
cross multiply
2*2=2(v-u)
4=2(v-u)
4/2=v-u
v-u=2m/s
v-u is the change is velocity.