Identify the energy possessed by a rolling stone.

$A$ $2 \, m$ high person is holding a $25 \, kg$ trunk on his head and is standing at a roadways bus-terminus. How much work is done by the person (in $, J$)?

$A$ boy is moving on a straight road against a frictional force of $5\, N$. After travelling a distance of $1.5\, km$ he reaches a roundabout (Fig.) of radius $100\, m$. He moves on the circular path for one and a half cycles and then moves forward up to $2.0\, km$. Calculate the total work done by him against the frictional force.

$A$ man drops a $10 \, kg$ rock from the top of a $20 \, m$ ladder. What will be its kinetic energy when it reaches the ground? What will be its speed just before it hits the ground? (Take $g = 10 \, m s^{-2}$)

State whether the following statement is true or false:
Work done by a force depends upon how fast work is done.

How many watts are there in $1$ horsepower (in $watts$)?