A 1 kg ball and a 10 kg ball are dropped from a height of 10 m at the same time. In the absence of air resistance,

O the 10 kg ball will take 10 times the amount of time to reach the ground.
O the two balls will hit the ground at the same time. 0 there is not enough information to determine which ball will hit the ground first.
O the 10 kg ball will hit the ground first.
O the 1 kg ball will hit the ground first.

the two balls will hit the ground at the same time.

Explanation:

The time of dropping, in the following equation, is related to both the distance travel s and the gravitational acceleration g, which are the same for both ball (if we neglect air resistance), no matter what their mass are.

So the time it takes to drop 2 balls are the same. They will hit the ground at the same time.

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .

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.