Question

Two pole-vaulters just clear the bar at the same height. The first lands at a speed of 8.50 m/s, and the second lands at a speed of 8.80 m/s. The first vaulter clears the bar at a speed of 1.50 m/s. Ignore air resistance and friction and determine the speed at which the second vaulter clears the bar.

Answer 1

landing speed =starting speed
v₀₁ = 8.5 m/s, v₀₂ = 8.8 m/s,
v₁ = 1.5 m/s, v₂ = ?

h=(v₁²-v₀₁²)/2g,
h=(v₂²-v₀₂²)/2g,
(v₁²-v₀₁²)/2g=(v₂²-v₀₂²)/2g,
v₂=sqrt(v₁²+v₀₂²-v₀₁²) =
= sqrt(1.5²+8.8²-8. 5²)= 2.73 m/s.

Answer 2

2.73

Answer 3

2.73