Mark Stone glides off the ice onto the bench at a velocity of 3.38 m/s. He is slowed at a constant rate of 4.7 m/s². How fast is Mark Stone moving when he slit 0.23 m down the bench?

Question

Mark Stone glides off the ice onto the bench at a velocity of 3.38 m/s. He is slowed at a constant rate of 4.7 m/s². How fast is Mark Stone moving when he slit 0.23 m down the bench?

(help show work)

Answer 1

Vi = 3.38

a = - 4.7
v = Vi + a t
x =Vi t + (1/2) a t^2
0.23 = 3.38 t - 2.35 t^2
2.35 t^2 - 3.38 t + 0.23 = 0
t = .0716 or 1.37
we want the first time, not the second as he comes back after stopping
v = 3.38 - 4.7 * .0716 = 3.04 m/s