Question

A skater is gliding on a smooth ice surface. What happens to his mechanical energy as he skates?
(a) It increases
(b) It decreases
(c) It becomes zero
(d) It remains constant

April 24, 2024

Answer

(d) It remains constant

Reason — As the skater glides across the ice, he possess kinetic energy due to his movement. The potential energy remains constant as there is no significant change in height. Assuming a smooth ice surface with no friction or air resistance, the external forces are absent, hence, according to the principle of conservation of mechanical energy, the total mechanical energy (KE + PE) of the skater remains constant.

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