Forces Chapter 1.
5
12 A uniform beam is pivoted at its centre. The beam is balanced by three weights in the positions
1. A uniform beam is pivoted at its centre. The beam is balanced by three weights in the positions shown.
shown.
0.50 m
0.40 m d
300 N 350 N 100 N
What is the length
What isdthe
? length d ? 5
A 0.020m B 0.050m C 0.20m D 0.48m
A 0.020 m B 0.050 m 7 C 0.20
A diver m
of weight 500 N Dstands
0.48atmthe end of a springboard that is 2.0 m
point P.
2. A diver of weight 500N stands at the end of a springboard that is 2.0m long and is fixed at point P.
The springboard has a weight of 500 N. The centre of mass of the
springboard is in the centre of the board.
© UCLES 2017 5054/11/M/J/17
What is the total moment about point P of the diver and the
board?
A 500Nm B 750Nm P
5
C 1000Nm D 1500Nm 2.0 m
10 Four objects of equal mass rest on a table. The centre of mass of each object is labelled G.
3. Four objects of equal mass rest on a table. TheThe centre of masshas
springboard ofaeach object
weight of 500is
N.labelled G.of mass of the springboa
The centre
Which object
Which is the leastisstable?
object the least stable? the board.
A B C What is theDtotal moment about point P of the diver and the board?
A 500 N m B 750 N m C 1000 N m D 1500 N m
G
8 A tennis ball of mass 56 g is travelling at 1500 metres / minute.
G
G G
Which expression is equal to the kinetic energy, in joules, of the tennis ball?
A 1
2
× 0.056 × (25)2
B 1
2
× 0.056 × (1500)2
4. A
11 Forces of length of2.0
4.0 N and thread isaattached
N act at point. to a lamina at point P, as
C 21 × 56 × (25)2 x P F
shown in the diagram. lamina
Which scale diagram shows the forces that have a resultant of 4.0 N? w
The lamina is free to rotate about point Q. TheDtension 2
1
× 56in× (1500)2 y
z
the thread is F.
A B
What is the moment of F about Q? Q
9 In a hydroelectric power station, 4.2 × 105 kg of water passes through the tur
A Fw B Fx C Fy D Fz
The turbines are at a height of 50 m below the surface of the reservoir. T
2.0 N
2.0 N strength g is 10 N / kg.
5. Four solid objects are made from the same material and
Assuming there are no energy losses, what is the power output of the power
have equal4.0
volumes.
N Which object is the most stable?
4.0 N
A B C A 8.4 × 103 WD B F × 104 W
8.4 C 2.1 × 107 W D 2.1 × 108 W
F
C D
Fw Fx Fy Fz
2.0 N 2.0 N 4.0 N
4.0 N
F CAIE O’ Level Physics 5054| Worksheet 2 SEMC 1
12 A student calculates his power in running up a flight of stairs. He measures the vertical height of
F
Forces Chapter 1.5
4
6.
2 Fig. 2.1 shows apparatus used to investigate the turning effect of a force. For
Examiner’s
Use
newton meter
pivot uniform metre rule
20 cm
40 cm
4.0 N
Fig. 2.1
The uniform metre rule is freely pivoted at its centre.
The newton meter is 20 cm from the pivot and a 4.0 N weight is 40 cm from the pivot.
The metre rule is in equilibrium.
(a) State the principle of moments for a body in equilibrium.
..........................................................................................................................................
..........................................................................................................................................
...................................................................................................................................... [1]
(b) Calculate the reading on the newton meter.
reading = .................................................. [2]
(c) The weight of the metre rule is 1.2 N.
Calculate the size of the force exerted on the metre rule by the pivot.
force = .................................................. [2]
CAIE O’ Level Physics 5054| Worksheet 2 SEMC 2
© UCLES 2013 5054/21/M/J/13
