The diagram depicts a block P, with mass $M$, joined by a string that runs over a frictionless pulley to a block Q, with mass $m$. Block P travels up the slope at a constant speed $v$. The slope makes an angle $\theta$ with the horizontal. The acceleration of free fall is $g$. The resistive forces acting on the blocks are negligible. Which expressions show the energy transferred to block P per unit time? 1. $mgv$ 2. $Mgv\sin\theta$ 3. $(M+m)gv$
- A1 and 2
- B1 only
- C2 and 3
- D2 only