1. What is the minimum speed that a glider must fly to make a perfect vertical circle in the air if the circle has a radius of 200.0 m?
2.A driver is negotiating a turn on a mountain road that has a radius of 40.0 m when the 1600.0-kg car hits a patch of wet road. The coefficient of friction between the wet road and the wheels is 0.500. If the car is moving at 30km/ h, determine if it skids off the road.
Answers & Comments
Verified answer
1)
The minimum speed is achieved with centripetal acceleration equal to the acceleration of gravity:
a = g = V² / R
From here:
V = √ (g · R) = √ (10 · 200) ≈ 140 m / s or 500 km / h
2)
Find the friction force:
Ftr = μ * m * g = 0.5 * 1600 * 10 = 8 000 N
Find the radius of rounding.
V = 30 km / h ≈ 8.33 m / s
From the formula:
F = m * V² / R
R = m * V² / F = 1600 * 8.33² / 8000 ≈ 14 m
Answer: "drift" will not.