Question

At the start of his race, an 88-kg runner pushes against the starting block, exerting an average force of 1700 N . The force that the block exerts on his foot points 20∘ above the horizontal.Determine the horizontal speed of the runner after the force is exerted for 0.34 s .

Answer 1

F = m * a
1700 N = 88 kg * a
a = 1700 : 38
a = 19.318 m / s²
v = a * t = 19.318 m/s * cos 20° * 0.34 s=
= 19.318 m/s² * 0.93969 * 0.34 s =
=18.15 m/s² * 0.34 s = 6.171 m/s
Answer:
The horizontal speed of the runner after the force is exerted for 0.34 s
is 6.171 m/s.