QUESTION 2 (Start on a new page.) Two boxes, P and Q. resting on a rough horizontal surface, are connected by a light
inextensible string. The boxes have masses 5 kg and 2 kg respectively. A constant
force F. acting at an angle of 30° to the horizontal, is applied to the 5 kg box, as shown
below.
The two boxes now move to the right at a constant speed of 2 m-s1
F
P
30°
2 m-s1
string
5 kg
2 kg
Rough surface
2.1
State Newton's First Law of Motion in words.
2.2
Draw a labelled free-body diagram for box Q.
Box P experiences a constant frictional force of 5 N and box Q a constan
frictional force of 3 N.
2.3
Calculate the magnitude of force F.
The string connecting P and Q suddenly breaks after 3 s while force Fiss
being applied
Learners draw the velocity-time graph for the motion of P and Q before
after the string breaks, as shown below.
N
2
Velocity (m-s'')
1
2 3
7 Time (s)​