ASSIGNMENT
(SUBMISSION DATE 29/08/2022)
TOPIC:MOTION IN A STRIGHT LINE,ENERGY &NEWTONS LAW OF MOTION
1) Find acceleration of an object of mass 0.2 kg when a force of 0.2N act on
it .If the object accelerated from rest ,find the distance travelled in 1/4
minutes.
2) Niagara falls are 50 m high . Calculate potential energy of 5000 g of water at
the top, relative to the bottom. What is the Kinetic energy of this water just
before it reaches the bottom , what happen to the energy after water reach
the bottom?
3) A body of mass 0.5 kg and initially at rest , is subjected to a force of 2 N
for 1s. Calculate a) the change in momentum of the body during the
second. b) The change of kinetic energy of the body during the second.
4) A ball of mass 100 g falls from a height of 3 m on to the horizontal surface
and rebounds to the height of 2 m. Calculate the change (i) in momentum
(ii) in kinetic energy of the balls when it strikes the surface.
5) A body of mass 4 kg is acted on by a constant force of 12 N for 2 s.
Calculate the kinetic energy of the body gained at the end of the time.
6) Two identical free- running trolleys are on smooth horizontal runway. One
trolley is at rest and the other approaching it at a constant speed of 20 cm/s.
After impact two trolley move together at 10 cm/s. Explain this result ,
stating the principle involved.
7) A trolley A of mass 2 kg travelling at 5 m/s collide with a stationary trolley
B of mass 3 kg. After the collision the two travel on together at 2 m/s.
a) What is the momentum of A before the collision?
b) What is the momentum of A after the collision?
c) Account for the change in the momentum of A.
d) What's the kinetic energy of A before the collision?
e) What's kinetic energy of each trolley after the collision?
f) During the collision, kinetic energy gained by B is less than the kinetic
energy lost by A . How much kinetic energy is unaccounted for , and
what has become of it.
9.
a) Define momentum and kinetic energy
b) show that the momentum and kinetic energy of a body can be related on
the following formula.
K.E =p²/2m
Where K.E is kinetic energy, p is linear momentum, m is mass of a body.
10. a) A car travel with velocity of 18 km/h. It then accelerates uniformly and
travels a distance of 50 m .If the velocity reached is 54 km/h. Find the acceleration
and the time to travel this distance.
b) A stone is thrown horizontally with an initial velocity of 15 m/s from a
tower 20 m high
i) How long does it take to reach the ground?
ii) At what distance from the base of the tower does the stone reach the
ground?