A ping-pong ball weighs 0.025 N. The ball is placed inside a cup that sits on top of a vertical spring. If the spring is compressed 0.055 m and released, the maximum height above the compressed position that the ball reaches is 2.84 m. Neglect air resistance and determine the spring constant.

The energy stored in the spring is used to throw the ball upwards. Let the height reached be h

stored energy of spring = 1/2 k y², k is spring constant and y is compression created in the spring

stored energy of spring = potential energy of the ball

1/2 k y² = mgh, m is mass of the ball, h is height attained by ball

.5 k x. 055² =.025 x 2.84

.0015125 k =.071

k =.071 /.0015125

= 46.9 N / m.