4. The figure shows two different frictionless ramps. The heights y, and y2 are the same for both ramps. If a block of mass m is released from rest at the left- hand end of each ramp, which block arrives at the right-hand end with the greater speed? (i) block I; (ii) block II; (iii) the speed is the same for both blocks. Explain your reason. Block I Block II m m y2 y2 不为-

4. The figure shows two different frictionless ramps. The heights y, and y2 are the same for both ramps. If a block of mass m is released from rest at the left- hand end of each ramp, which block arrives at the right-hand end with the greater speed? (i) block I; (ii) block II; (iii) the speed is the same for both blocks. Explain your reason. Block I Block II m m y2 y2 不为-