A contestant in a winter games event pushes a 59.0-kg block of ice across a frozen lake with a force of 25 N at 22.0° below the horizontal as shown in Figure (a) below, and it moves with an acceleration of 0.390 m/s2 to the right.
(a) What is the normal force exerted by the lake surface on the block of ice?
(b) Instead of pushing on the block of ice, the contestant now pulls on it with a rope at the same angle above the horizontal as in part (a), and with the same magnitude of force. Now what is the normal force exerted by the lake surface on the block of ice?

Question

A contestant in a winter games event pushes a 59.0-kg block of ice across a frozen lake with a force of 25 N at 22.0° below the horizontal as shown in Figure (a) below, and it moves with an acceleration of 0.390 m/s2 to the right.
(a) What is the normal force exerted by the lake surface on the block of ice? 
(b) Instead of pushing on the block of ice, the contestant now pulls on it with a rope at the same angle above the horizontal as in part (a), and with the same magnitude of force. Now what is the normal force exerted by the lake surface on the block of ice?