Answer : 5m/s
Explanation:the formular for velocity is distance /time or you can say displacement /time. Then it would then be
100/20 =5m/s
To solve this exercise, it is necessary to apply the concepts of conservation of the moment especially in objects that experience an inelastic colposition.
They are expressed as,

Where,
= mass of the skier
= mass of the cat
= initial velocity of skier
= initial velocity of cat
= final velocity of both
Re-arrange to find V_f we have,



Once the final velocity is found it is possible to calculate the change in kinetic energy, so




Therefore the amount of kinetic energy converted in to internal energy is 819J
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.
The formula for the rotational kinetic energy is

where I is the moment of inertia. This is just mass times the square of the perpendicular distance to the axis of rotation. In other words, the radius of the propeller or this is equivalent to the length of the rod. ω is the angular velocity. We determine I and ω first.

ω = 573 rev/min * (2π rad/rev) * (1 min/60 s) = 60 rad/s
Then,
