A baseball player hits a baseball, changing its momentum by 15\, \dfrac {\text{kg}\cdot \text m}{\text s}15 s kg⋅m ​ 15, start fraction, start text, k, g, end text, dot, start text, m, end text, divided by, start text, s, end text, end fraction. The net force on the ball is 7{,}100\,\text N7,100N7, comma, 100, start text, N, end text.

Distance covered, s = 8ft - 4ft = 4 ftinitial velocity, u = 34 ft/sthe acrobat is moving upwards and therefore, a = -g = -9.81 m/s^2 = 32.19 ft/s^2applying equation of motion; s = ut -1/2gt^2then,4 = 34t -1/2*32.19t^24 = 34t - 16.095t^2rearranging; -16.095t^2 + 34t - 4 = 0solving the quadratic equation; t = {-34 +/- sqrt [34^2 - 4(-16.)]}/2(-16.095) = 1.06 +/- 0.93 = 0.13 or 1.99the acrobat will take 0.13 seconds to be at 8 ft above the ground. additionally, once at the maximum height, the acrobat will move down and be at the same spot (that is height) after 1.99 seconds moving down.

The sounds will have a high pitch because the metal is vibrating quickly