Question
(a) (i) State what is meant by the moment of a force about a point.
……………………………………………………………………………………………………………………. [1]
(ii) Fig. 2.1 shows a large crane on a construction site lifting a block of mass 14 000 kg.
Calculate the moment about A due to the 14 000 kg block suspended from B.
moment = …………………………………………… [2]
b (i) Speed is a scalar quantity and velocity is a vector quantity. State the difference between a
scalar quantity and a vector quantity.
………………………………………………………………………………………………………………………….
……………………………………………………………………………………………………………………. [2]
(ii) Write down one other scalar quantity and one other vector quantity.
scalar quantity …………………………………………………………………………………………………….
vector quantity …………………………………………………………………………………………………….
[2]
c Fig. 2.2 shows two forces acting on an object. 
Draw a scale diagram to determine the resultant force acting on the object. State the scale you use.
scale ……………………………………………………..
magnitude of resultant force = …………………………………………………..
direction of resultant relative to the direction of the 20 N force = …………………………………………………..
[4]
[Total: 11]
Answer/Explanation
Ans:
(a)(i) (moment of a force) is the turning effect (about a point / pivot)
(a)(ii) 2.8× 
Nm (moment = ) Fd in any form
(b)(i) scalar / speed has magnitude only OR scalar / speed has no direction vector / velocity has magnitude and direction
(b)(ii) any scalar quantity any vector quantity
(c)
correct triangle or parallelogram drawn resultant force (including correct arrow)
scale 1 cm = 4 N or 1 cm = 5 N
140 – 47 N AND 33° – 40° (anticlockwise from 20 N)