7.6
analysing the one
importance of force in
life
d
45 salmah's father shifted 40 bricks
over a distance of 1.5 m in one
minute. each brick weighs 20 n.
calculate salmah's father's
power.
a 10 watts c20 watts
b 15 watts d 25 watts
wly
i only
application of power
40 the number of units of work
done in one unit of time is
called
a energy
c force
b power dload
41 komala has used 0.4 kw of
power to carry a pail of water,
over a distance of 5 m, in 3
seconds. calculate the weight
of the load.
a 24 n c 120 n
b 48 n d 240 n
49 life will be in a state of
disorder if forces do not exist in
this world. which of the
following statements is not
correct?
a everything in this world will
be floating
ng factors
one by a
alking up
stairs
erson
climb the
46 swee lin, who has a weight of
500 n, climbs upstairs in 10
seconds. the vertical height of
the stairs is 30 m. calculate the
power used to climb the stairs.
a 15 watts
b. 150 watts
c 1 500 watts.
d 15 000 watts
b every movement will not be
able to stop
c the shape of things cannot
be changed.
d the walls of buildings will
automatically collapse.
that
ne when
m the
42 a simple motor has a power of
18 w. calculate the time taken
by the motor to hoist a load
which has a mass of 4.5 kg to a
height of 4 m.
a 10 seconds
bject
en the
47 calculate the power of a
machine used to pull a car with
a mass of 500 kg over a distance
of 0.3 km, in 5 minutes.
a 3500 watts
b 4000 watts
c 4500 watts
d 5000 watts
instructions
а
lb c
i, ii, iii i. i only. ii, iii only
d
i only
b 15 seconds
c 20 seconds
d 25 seconds
ch the
43 a machine which has a power of
500 w can carry a load of 1000 n
over a distance of 400 m.
calculate the time taken by the
machine.
a 400 seconds
b 800 seconds
c 1 200 seconds
d 1 600 seconds
stance
50 forces are very important in
our daily life because it enables
i us to hold things
il us to change the shapes of
an object
iii vehicles, animals and
humans to move
48 a power of 120 watts will be
generated by a boy whose
weight is 3000 n if he
i does 120 joule of work in 1
second
ii walks a distance of 4 m in
100 seconds
hi moves a load of 240 n in 2
seconds
me
50
600
climb
ng
44 calculate the power to carry a
stone up a building to a height
of 30 m with a force of 200 n in
25 seconds.
a 120 watts
b 240 watts
c 1200 watts
d 2400 watts