A block of mass 22 kg is sliding along the ice at constant speed 5.0 m/s. Just ahead of it is a block of mass 29 kg sliding in the
same direction at constant speed 4.6 m/s. When the two blocks collide, the 29-kg block travels at a new speed of 7.2 m/s. What is
the new speed of the 22-kg block?

The new speed of 22 kg block is 1.57 m/s

Explanation:

Given-

Mass, = 22 kg

speed,  = 5 m/s

= 29 kg

= 4.6 m/s

New speed of , = 7.2 m/s

New speed of , = ?

This is the case of elastic collision.

So,

X  + X = X + X

22 X 5 + 29 X 4.6 = 22 X + 29 X 7.2

22 + 208.8 = 243.4

22 = 34.6

= 1.57 m/s

Therefore, the new speed of 22 kg block is 1.57 m/s

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

are there answer choices to this question? this seems like a question where you have options to choose from.