Answer:
28 m/s
Explanation:
According to the work-energy theorem, the work (W) done on the car is equal to its change in kinetic energy (ΔKE). Kinetic energy (KE) is half the mass (m) times the square of the speed (v).
W = ΔKE
W = ½ mv² − ½ mv₀²
W = ½ m (v² − v₀²)
v² − v₀² = 2W / m
Plug in values and solve for v₀.
(32 m/s)² − v₀² = 2 (3×10⁵ J) / (2.4×10³ kg)
v₀² = 774 m²/s²
v₀ = 28 m/s
Rounded to two significant figures, the initial speed of the car is approximately 28 m/s.
