A 23.0-kg child on a 4.00-m-long swing is released from restwhen the ropes of the swing make an angle of 25.0° with thevertical. (a) Neglecting friction, find the child's speed at thelowest position. m/s (b) If the actual speed of the child at thelowest position is 2.40 m/s, what is the mechanical energy lost dueto friction? J
