14. Exercises

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A metal beam, of mass 6 kg and length 2m, rests in a horizontal position on two supports that are at a distance of 40 cm from each end of the beam. A 1.2 kg mass is placed at one end of the beam.
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a) Find the magnitude of the reaction forces acting on the beam.
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b) What is the greatest mass that could be placed at the other end of the beam, if it is to remain in equilibrium?
</div>{{#NAVCONTENT:Answer|Answer 14.5|Solution a|Solution 14.5a|Solution b|Solution 14.5b}}
</div>{{#NAVCONTENT:Answer|Answer 14.5|Solution a|Solution 14.5a|Solution b|Solution 14.5b}}

Revision as of 19:12, 10 November 2009

       Theory          Exercises      


Exercise14.1

A uniform beam of mass 20 kg and length 3m rests on two supports as shown below.

Image:E14.1.GIF

(a) Find the reaction force exerted by each support.

(b) Find the greatest mass that can be placed at the left hand end of the beam.


Answer
Answer 14.1
Solution a
Solution 14.1a
Solution b
Solution 14.1b


Exercise 14.2

A plank has length 6 m. The plank is placed on a quayside with its mid-point at the edge of the quay, so that half of the plank sticks out over the water. A rock of mass m kg, which should be modeled as a particle is placed at the end of the plank which is on the ground. A person of mass 60 kg walks on the part of plank that is over the water. When the person is 1 m from the end the plank is on the point of tipping. Find m.

Image:E14.2.GIF

Answer
Answer 14.2
Solution
Solution 14.2



Exercise 14.3

A uniform beam has mass 20 kg and length 6 m. It rests on two supports that are 1.5 m from each end of the beam. A concrete block of mass 5 kg is placed at a point on the beam at a distance of 2.5 m from one end. Find the magnitude of the reaction forces exerted on the beam by the two supports.


Answer
Answer 14.3
Solution
Solution 14.3


Exercise 14.4

A uniform rod of mass 18 kg and length 6m rests on two supports.


Image:E14.4.GIF


a) Find the magnitude of each force exerted on the rod by the supports.

A particle is attached to the rod at the right hand end.

b) What is the greatest possible mass of the particle if the rod remains in equilibrium?


Answer
Answer 14.4
Solution a
Solution 14.4a
Solution b
Solution 14.4b


Exercise 14.5


A metal beam, of mass 6 kg and length 2m, rests in a horizontal position on two supports that are at a distance of 40 cm from each end of the beam. A 1.2 kg mass is placed at one end of the beam.

a) Find the magnitude of the reaction forces acting on the beam.

b) What is the greatest mass that could be placed at the other end of the beam, if it is to remain in equilibrium?


Answer
Answer 14.5
Solution a
Solution 14.5a
Solution b
Solution 14.5b
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