A car is driving around in a circle of radius 20 m around a

A car is driving around in a circle of radius 20 m around a level parking lot. There is a coefficient of static friction mu = 0.25 between the car and the road. What is the highest speed at which the car can move without slipping? a) 28.0 m/s b) 9.10 m/s c) 7.00 m/s d) 6.05 m/s e) 8.50 m/s A 220 kg roller-coaster car traveling horizontally at 28 m/s rolls into a giant horizontal spring that compresses 2.1 m before the car changes direction. What is the elastic spring constant of this spring? a) 36.4 kN/m b) 24.3 kN/m c) 43.0 kN/m d) 39.1 kN/m e) 41.6 kN/m

Solution

Conserving Energy

0.5mv^2 = 0.5kx^2

220*28^2 = k*2.1^2

k = 39.1 kN/m

Hence answer is d option