Car's Initial velocity (u) = 5 m/s
Car's Final velocity (v) = 0 m/s (Stop)
Acceleration of the car (a) = -1.5 m/s²
Equation used to solve this problem:

By substituting values in the equation, we get:

Displacement of the toy car (s) = 8.3 m
Answer
given,
mass of the piano = 170 kg
angle of the inclination = 20°
moves with constant velocity hence acceleration = 0 m/s²
neglecting friction
so, force required to pull the piano
F = m g sin θ
F = 170 × 9.81 × sin 20°
F = 570.39 N
so, force required by the man to push the piano is F = 570.39 N
W=ΔKE , W=-5000j
KEinitial=(1/2)mv² , KEfinal=0j
ΔKE=-(1/2)mv²
-5000=-(1/2)(100kg)v²
v=10 m/s