Question

Crime scene investigators find that a car hit the ground 60m from the point where it left the cliff. The cliff is 45 m high. Approximately what speed was the car going when it left the cliff (assume no air resistance)?

Answer 1

20 m/s

Step-by-step explanation:

In the y direction:

y = y₀ + v₀ᵧ t + ½ gt²

0 m = 45 m + (0 m/s) t + ½ (-9.8 m/s²) t²

t = 3.03 s

In the x direction:

x = x₀ + v₀ₓ t + ½ at²

60 m = 0 m + v (3.03 s) + ½ (0 m/s²) (3.03 s)²

v = 19.8 m/s

Rounded to one sig-fig, the car's velocity was approximately 20 m/s.