For an animal to move in one direction,its muscles must do all of the following except
A) exert a force in the opposite direction.
B) overcome the effects of friction.
C) exert a force in the same direction.
D) overcome the effects of gravity.
E) spend energy.

Question

For an animal to move in one direction,its muscles must do all of the following except  
A) exert a force in the opposite direction.
B) overcome the effects of friction.
C) exert a force in the same direction.
D) overcome the effects of gravity.
E) spend energy.

Quizplus · Accepted Answer

For an animal to move in one direction, its muscles must exert a force in the opposite direction to the intended movement (action-reaction principle), overcome friction and gravity, and spend energy. Exerting a force in the same direction as the movement would not contribute to the movement in the intended direction, making it the exception.

For an Animal to Move in One Direction,its Muscles Must