Question 1
An object of mass 50kg is suspended by two strings from points A and B as shown below. | |
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a) | Calculate the tension, Te in each of the strings. |
b) | If the distance A B is decreased, will the tensions in the strings increase, decrease or stay the same? Explain your answer. |
A uniform ladder of mass 15kg and length 2·5m is leaning against a smooth wall, as shown below. | |
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a) | Using the principle of moments, calculate the magnitude of the force exerted by the wall on the ladder. |
b) | Find the direction of the force exerted by the ground on the ladder. |
c) | Calculate the magnitude of the force exerted by the ground on the ladder. |
A set of uniform shelves is supported by two vertical pieces of wood. The forces exerted by the pieces of wood, in order to support the shelves, are F1 and F2. | |
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a) |
If each shelf has a mass of 1·5kg, calculate the magnitudes of the two forces, F1 and F2.
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b) |
An object of mass m1 = 4kg is placed in the centre of one of the shelves, as shown below.
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Calculate the new magnitudes of the forces, F1 and F2. | |
c) | A second object, of mass m2 = 6kg is now placed half way between the first object and the right hand support, as shown below. |
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Calculate the new magnitudes of the forces, F1 and F2. |
A vehicle is crossing a uniform bridge. The distance between the centre of gravity of the vehicle and the end, A, of the bridge is d (see diagram below). The weight of the bridge is W1 = 20000N and the weight of the vehicle is W2 = 7500N. F1 and F2 are the forces exerted by the supports on the bridge. |
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Show that the relation between the magnitude of F1 and the distance, d, is given by |
F1 = 23500 - (1500×d)
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A rock musician (very famous in the 1960’s and 1970’s) made a record inspired by the turning effects of forces in equilibrium. | |
a) | What was the name of the record and what year was it made? |
b)
| What was the name of the musician? |
c) | Find the names of the other three members of the group he was in when he became famous. |