14) Complete the Table Below to Identify the Physical Quantities As Scalars Or Vectors
Total Page：16
File Type：pdf, Size：1020Kb
14) Complete the table below to identify the physical quantities as scalars or vectors
Physical quantity Scalar or vector
Speed
Velocity
Distance
Force [2]
15) Diagram A shows a uniform rod balanced at its centre. The 10 N weight and the sandbag are positioned at equal distances from the pivot.
10 N pivot sandbag
DIAGRAM A
(a) What is the weight of the sandbag and its contents?...... N
[1]
A hole now appears in the sandbag and sand begins to trickle out.
(b) In what direction (clockwise or anticlockwise) will the rod tip as a result of the sand trickling out?
......
[1]
(c) In what direction (to the left or to the answer) must the 10 N weight move along the rod, if the rod is to return to the original horizontal (level) position?
......
[1] 16) The diagram below shows a car-park barrier.
1.35 m 0.9 m
STOP
pivot supporting F 150 N pillar
The weight of the barrier is 150 N and its centre of gravity is 0.9 in from the pivot.
(a) Calculate the size of the clockwise moment produced by the barrier’s weight about the pivot.
Show clearly your working out.
Clockwise Moment = ......
[3]
(b) Use your answer to part (a) to calculate the size of the force F on the left of the pivot which will just lift the barrier off the supporting pillar.
Show clearly your working out.
Force = ...... N
[3] 17) As a car races round a circular track, it experiences a centripetal force. In the diagram below the car is represented by a large black dot.
(a) Mark clearly with an arrow labelled F, on the diagram below, the direction of the centripetal force.
sports car
direction of motion
centre of circular track
[1]
(b) What provides the force which causes the centripetal force to keep the car moving in a circle.
......
[1]
(c) The car races around the track at a constant speed. Explain briefly why the car’s velocity is continually changing.
......
...... [1] 18) A steel spring is tested in the laboratory by loading weights onto it and measuring the extension produced by the weights. The graph shows a plot of weight against extension. The spring is 12 cm long before any weight is added.
Spring
Weights
50
40
30 Weight in N
20
10
0 0 1 2 3 4 5 Extension in cm
(a) The extension is directly proportional to the weight. From the graph, give two reasons why we know this to be the case.
(i) ......
(ii) ......
[1] (b) What is the total length of the spring when a weight of 28 N is added?
Length ...... cm [2]