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**1. Homework Statement**

A skier swoops down a hill and over a ramp as in the attached figure. She starts from rest at a height of 16 m, leaves the 9.0 m ramp ata an angle of 45 degrees, and justt clears the hedge on her way down, making an angle of 30 degrees with the vertical as she does. Assuming that there is no friction, and that she is small compared to the dimensions of problem, solve for H, the height of the hedge in metres.

See Diagram View attachment Diagram.doc

Is it true that angle of decline and incline will have no effect in this problem?

The answer is 2 m but I still don't known how to approach?

**2. Homework Equations**

KE = 0.5 * mass * (speed)^2

PE = mass * g * height

**3. The Attempt at a Solution**

I don't know if this helps, but I think that roller coaster approach can be taken for this question.

Which would mean that the mechanical energy will be conserves and the only form of force would be from gravity.

We will also have Potential Energy (that will be max at top of curve and kenetic energy (that will be 0 at top and increase as skier comes down).

KE = 0.5 * mass * (speed)^2

PE = mass * g * height

The skier leaves the ramp with an initial velocity of vi at an angle of 45 degrees to horizontal.

Change in y=16-9=7m

Gravitaional Potential=mgy

Kenetic Energy=0.5mv^2

At height of 9 m

Eg-Ek=0

mgy=0.5mv^2=0

v=sqrt(2gy)

= 11.71 m/s

Horizontal velocit is now 8.28 m/s

Vertical velocity is 8.28 m/s too.

I don't know how this will help in solving for the height of hedge. How would we use energy approach?

I need help really soon

Thanks