Question

A bicycle coasting at 6.0 m/scomes to a 5.0-mlong, 1.0-mhigh ramp. What is the bicycle's speed as it leaves the top of the ramp?

Answer 1

SOLUTION :

K. E. at the beginning of ramp = 1/2 m v^2 = 1/2 m (6)^2 = 18 m   (N-m) 

P. E at the top of the ramp = m g h = m * 9.8 * 1.0 = 9.8 m    (N-m)

Let the speed at the top of ramp be V m/sec.

So K.E at the top of the ramp = 1/2 m V^2 

So, aș per energy conservation :

Total energy at the beginning of the ramp = Total energy at the top of the ramp

=> 18 m = 9.8 m + 1/2 m V^2 

=> 18 = 9.8 + 1/2 V^2

=> V^2 = (18 - 9.8) * 2 = 16.4 

=> V = sqrt(16.4) = 4.05 m/sec 

So, bicycle speed as it leaves the top of the ramp = 4.05 m/sec (ANSWER).