Q. 66

Expert-verified
Found in: Page 202

### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

Book edition 4th
Author(s) Randall D. Knight
Pages 1240 pages
ISBN 9780133942651

# Sam (75 kg) takes off up a 50-m-high, 10­ frictionless slope on his jet-powered skis. The skis have a thrust of 200 N. He keeps his skis tilted at 10­o after becoming airborne, as shown in FIGURE CP8.66. How far does Sam land from the base of the cliff?

Sam will land at a distance from cliff is : 57.41 meters.

See the step by step solution

## Step1: Given Information

Mass = 75 kg
Takes off at 50 m heightAngle of projection 10o The skis have a thrust of 200 N.Ski is tilted at 10o after becoming airborne.

## Step2: Explanation

We know that work done by a constant force F in moving a body a distance d is given by

W=F d.

Potential energy of a mass at height h is given as mgh.

KE of an object moving with velocity v is given by 1/2mv2

The displacement S of an object moving with acceleration and initial speed u is given by

From the law of conservation of energy

Kinetic energy at the release point is equal to work done minus potential energy

Substitute the given values and calculate v

Now find time it takes for Sam to touch down

we get

t= - 2.912 s, and 3.501 s

Drop the negative value so t=3.501 sec.

So total distance will be horizontal component of velocity multiplied by time