Question

4.A child of mass 30kg skates down from the top of a ramp having a constant slope of 15^(@). The child's speed increases from 1.5ms^(-1) to 3.0ms^(-1) as she reaches the bottom of the ramp.A force of kinetic friction of magnitude 50N opposes her motion.Draw the appropriate force diagram and determine the length of the ramp. Take g=10ms^(-2) .​

Answer 1

Thus the length of the ramp is S = 21.12 m

Explanation:

Considering the force acting parallel to the ramp from the diagram

30 g sin(15°) - 50 =30 a

Where a is the acceleration of the box,

a = 0.87 ms^-2

To find the the length of the ramp s,

Applying equation v^2 = u^2+2as  

13^2  = 11.5^ 2  + 2 × 0.87 × s

Applying equation S = 21.12 m

Thus the length of the ramp is S = 21.12 m