. In the equation s =v0t + 1/2at2 ,s,v0 and a are magnitudes of the respective vector quantities.
Write down the equation in vector form.
A vector of magnitude 5 units is inclined at an angle 37° to the x axis . Find the magnitudes
of the vector components along x and y axis. ( 5- marks )
SECTION (B)
Answer ALL Questions
Answer any FOUR Questions
(a) Is work a vector or scalar? Define “energy”. A wooden sphere of mass 0.15 kg is thrown
with a velocity of 30 ms-1 .Find the kinetic energy of the sphere. (4-marks )
(b) Define “work” . Write down the unit of work in SI system. A woman push a child, who is
riding a tricycle, with a 200N force. The tricycle moves a distance of 2m and the work done
by the woman is 100J. Find the angle between the force and the displacement. (4-marks )
(a) Define speed and velocity such that the two may be distinguished. An object moves with
an initial velocity of 4ms-1 . If it moves with a uniform acceleration of 2ms-2 find the
displacement after 20 s. (4-marks )
(b) A body moving with a constant acceleration reach the velocity 4ms-1 after 10s. If the
body start from rest , find the velocity after (a) 12s (b) 14s (c) 16s (d) 18s. Draw the
velocity time graph for the interval 10 s to 18 s. From the graph , find the velocities at
8s and 20s. (4marks )
P.T.O →
(a) State law of conservation of momentum. ( 4 marks )
A 30g bullet moving at a constant velocity hits a wooden block of mass 3kg and continues
to travel at the velocity of 2 ms-1 together with the block. What is the velocity of the bullet
when it hits the block?
(b)A 0.2kg marble is at rest on a smooth table. Another marble of mass 0.1 kg moving at
a constant velocity of 10 ms-1 towards the east hits this marble and it recoils to the west
with the velocity of 5ms-1. Find the velocity of the marble which was at rest? ( 4 marks )
(a) In order to weight a body in the laboratory, a uniform plank of wood AB 3 m long and
having a mass of 8kg is pivoted about a point 0.5 m from A. The boy stands 0.3m from A
and a mass of 2 kg is placed 0.5m from B in order to balance the plank horizontally .
Calculate the mass of the boy. ( 4 marks )
(b) A heat resistant glass at 15℃ is fully filled with 250 cm3 of glycerine . If the temperature
increases to 25℃ how much glycerine overflows? The coefficient of volume expansion of
glycerine is 5.1 x10-4K-1 and that of heat resistant glass is 0.09 x 10-4K-1. ( 4 marks )
(a) According to observation and measurements the farthest galaxies are at a distance of
1026
