ksion

. 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 )

1. Which of the following quantities are scalars and which are vectors?
   (a) speed (b) velocity (c) average velocity (d) acceleration (e) displacement.
   A particle starting from rest moves along a straight line with a constant acceleration of 2 ms-2.
   What is the velocity of the particle 9 s after it started from rest? ( 5- marks )

SECTION (B)
Answer ALL Questions
Answer any FOUR Questions

1. (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 )

2. (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 →

1. (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 )

2. (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 )

3. (a) According to observation and measurements the farthest galaxies are at a distance of
   1026 m from the earth . When space travel become highly advanced do you think that man
   will be able to visit those galaxies?(1 year ≃ 108s ) ( 4 marks )
   (b) A man walks 2 mi east and then 3 mi in a direction 60° north of east . Find the magnitude
   of his resultant displace from his starting point. ( 4 marks )