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# Form 4 Physics Uniform Circular Motion Questions and Answers

Form 4 Physics Uniform Circular Motion Questions and Answers.

Browse though questions and video solution for the Form 4 Physics topic on uniform circular motion. The answers are detailed and well explained.

Lessons (**20**) * SHARE*

- 1.
State the meaning of the term “radian” as a unit of measure.

2m 22s - 2.
Figure 4 shows a stone whirled in a vertical circle. On the axes provided, sketch a graph of tension against time as the stone moves through point A, B, C and D. (3 marks)

3m 7s - 3.
State three conditions necessary for a driver to negotiate a bend on a flat level road at a relatively high speed.

3m 14s - 4.
a).When a bus goes round a bend on a flat road, it experiences a centripetal force. State what provides the centripetal force. b).State the purpose of banking roads at the bends. c).A student whirls a stone of mass 0.2Kg tied to a string of length 0.4m in a vertical plane at a constant speed of 2 revolutions per second.(Take
acceleration due to gravity, #g= 10ms^2#)

0m 0s - 5.
(a) Figure 13 shows a pendulum bob suspended by a thread moving in a horizontal circle.
(i) Name two forces acting on the pendulum bob as it moves (ii) State what happens to each of the forces when the angular velocity of the pendulum bob is increased.
(iii) State two applications of uniform circular motion in daily life.

3m 36s - 6.
(a) State two ways in which the centripetal force on a body of mass m can be increased. (b) Figure 7 shows an object at the end of a light spring balance connected to a peg using a string. The object is moving in a circular path on a smooth horizontal table with a constant speed.
(i) State what provides the centripetal force....

8m 46s - 7.
Figure 10 shows the path of an object of mass m attached to a string of length r when whirled in a vertical circle circle at a constant speed V.A is the highest point on its path.
i).State the forces that provide the centripetal force on the when it is at point A.
ii).Indicate with an arrow on the diagram the direction of the net force F acting on the object when it is at A.

2m 9s - 8.
Figure 11 shows a stone attached to the end of a string moving in a horizontal circle with a uniform speed of 2m/s. When the stone reaches point X on the circle, the string breaks.
i)Indicate on the diagram with an arrow, the direction of the motion of the stone when the string breaks.
ii).State the magnitude of the velocity after the string breaks. iii).Give a reason for your answers in i) and

3m 3s - 9.
Figure 5 below shows a mass of 200 g connected by a string through a hallow tube to a mass of 0.5Kg. The 0.5kg mass is kept stationary in the air by whirling the 200g mass round in a horizontal circle of radius 1.0 metre. Determine the angular velocity of the 200g mass.

2m 23s - 10.
a).Define angular velocity. b).Three masses are placed on a rotating table at distances 6cm, 9cm and 12 cm respectively from the centre of rotation. When the frequency of rotation is varied it is noted that each mass slides off at a different frequency of rotation of the table

7m 49s - 11.
A turntable of radius 8cm is rotating at 33 revolutions per second .Determine the linear speed of a point on the circumference of the turntable.

2m 32s - 12.
a).State what is meant by centripetal acceleration. b).Figure 12 shows masses A, B and C placed at different points on a rotating table. The angular velocity ‘w’ of the table can be varied.
i).State two factors that determine whether a particular mass slides off the table or not. ii).It is found that the masses slide off at angular velocity #W_A# ,#W_B# and #W_C# respectively.

6m 6s - 13.
Figure 6 shows the path taken by a matatu travelling on horizontal ground (a winding road).
The speed of the matatu is constant. Identify with reason the point along the path which a load placed loosely on the rack(carrier) of the matatu is most likely to roll off.

2m 26s - 14.
a).Define the tem angular velocity. b).A body moving with uniform angular velocity is found to have covered an angular distance of 170 radians in t seconds. Thirteen seconds later it is found to have covered a total distance of 300 radians .Determine t. c).Figure 8 shows a body of mass m attached to the centre of a rotating table with a string whose tension can be measured.

17m 0s - 15.
A car of mass 800 kg moves on a circular track of radius 20m.The force of friction between the tyres and the tarmac is 4800N.Determine the maximum speed at which the car can be driven on the track without skidding.

1m 59s - 16.
A body mass 0.50kg is attached to the end of a string of length 50cm and whirled in a horizontal circle .If the tension in the string is 81N, determine the velocity of the body.

1m 33s - 17.
A child of mass 20kg sits on a swing of length 4m and swings through a vertical height of 0.9 m as shown in the figure 2.
Determine; i).Speed of the child when passing through the lowest point.
ii).Force exerted on the child by the seat of the swing when passing through the lowest.

3m 28s - 18.
A small object moving in a horizontal circle of radius 0.2m makes 8 revolutions per second. Determine its centripetal acceleration.

1m 53s - 19.
Figure 20 shows a ball being whirled in a vertical plane.
Sketch on the same figure the path followed by the ball if the string cuts when the ball is at the position shown in the figure.

0m 50s - 20.
Figure 15 shows two masses 0.1kg and 0.2kg connected by a string through a hole on a smooth horizontal surface.
The 0.1kg mass rotates in a horizontal circle of radius 3cm. Calculate the angular velocity of the mass when the
system is in equilibrium.

3m 32s