**PHY 1151**

__Chapter 7; Work and Kinetic Energy__

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Chapter 7 | Course Calendar
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**D7.1 **How much work
is done by gravity on a skier weighing 600 N who slides 500 m down a hill
(measured along the hill) which makes an angle of 30° with the horizontal
as sketched in the figure?

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a) How much work is done on the puck by the stick as it moves a distance of 0.7 m?

b) What will be the puck's speed after it has moved that 0.7 m, assuming it started at rest?

c) From there the puck leaves the stick and slides across the floor. How far will it slide?

P = F v (assuming F and v are parallel)

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**mass (kg)**
**speed (m/s)**
**A**
**0.225 kg**
**0.85 m/s**
**B**
**0.225**
**0.90**
**C**
**0.250 **
**0.35**
**D**
**0.250**
**0.50**
**E**
**0.267**
**0.65**
**F**
**0.315**
**0.82**
**G**
**0.450**
**0.45**
**H**
**0.450**
**0.52****KE = ( ^{1}/_{2})
m v^{2}**

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**| ToC,
Chapter 7 | Course Calendar
|**

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**(c) 2005, Doug Davis; all rights reserved.**