Download Basic Physics and Materials Mechanics Sheet 1 1. A force of 5N and

Basic Physics and Materials
Mechanics Sheet 1
1. A force of 5N and a force of 3N act on the same point at right angles to each other. What is the
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magnitude and direction of the resultant force? (5.8N at 30.9 )
2. A constant force acts on a 5 kg object and reduces its velocity from 7 m/s to 3 m/s in a time of 3s
.What is the magnitude of the force? (-6.7N)
3. A ball is kicked off the top of a cliff with a horizontal velocity of 20 m/s and no vertical component of
velocity. It hits the ground 3 s later. How high is the cliff and how far from the cliff does it land ?
(60m, 44m)
4. A gun fires a shell which hits a target on the same level as the gun and is 1300m away. The muzzle
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velocity is 120 m/s. What angle of elevation to the horizontal was the barrel at? (31 )
5. A powered hang glider is moving at 15 m/s parallel to and 100m above flat ground. The flyer wishes to
hit Dr. Mustoe, who is sitting on a park bench, with a bag of flour. He intends to release the bag
without giving it any velocity components relative to the hang glider. How far away from the bench
should he release the bag? (67.8m)
6. A 600kg car is moving on a level road at 30 m/s. How large a retarding force is required to stop it in a
distance of 70m and what is the required coefficient of friction between tyre and road for this to be
possible? (-3.86kN, 0.66)
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7. A 20kg box sits on an incline of 30 . If the coefficient of sliding friction between the box and incline is
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0.3 what is the acceleration of the box down the incline? (2.35 m/s )
IFP Problem Sheets. Semester 1