Question

A small block has constant acceleration as it slides down a frictionless incline. The block is released from rest at the top of the incline, and its speed after it has traveled 7.80 m to the bottom of the incline is 3.8m / s. What is the speed of the block when it is 4.40m from the top of the incline?

Answer 1

9.00 m/s

Step-by-step explanation:

Energy is conserved.

KE + PE = KE + PE

½ mv₁² + mgh₁ = ½ mv₂² + mgh₂

½ v₁² + gh₁ = ½ v₂² + gh₂

½ (3.8 m/s)² + (9.8 m/s²) (7.80 m) = ½ v² + (9.8 m/s²) (4.40 m)

83.66 m²/s² = ½ v² + 43.12 m²/s²

v = 9.00 m/s