Page 1 - HA
P. 1

SAI INTERNATIONAL SCHOOL

                                                         PHYSICS
                                                         CLASS IX

                                                 HOME ASSIGNMENT-24
               OBJECTIVE

               MCQ (BOARD)
               1.  When two bodies move towards each other and after collision move away in
               opposite directions, we observe a change in the temperature. The change is a rise in
               the temperature of two bodies because a part of kinetic energy is converted into

               a.  electrical energy
               b.  nuclear energy

               c.  mechanical energy

               d.  heat energy
               2. Which one of the following is not the unit of energy?


               (a) Kilowatt

               (b) Kilowatt hour


               (c) Joule


               (d) Newton meter



               SUBJECTIVE

               1. Can any object have momentum even if its mechanical energy is zero? Explain.
               2. Can any object have mechanical energy even if its momentum is zero? Explain.



               NUMERICALS
               1. A ball is dropped from a height of 10m. If the energy of the ball after striking the
                                                                         2
               ground, how much high can the ball bounce (g = 10m/s ).
               2. A body of mass 20kg is lifted up to 10m height. Calculate its potential energy if the
               body  is  allowed  to  fall.  Find  its  potential  energy  before  it  touches  the  ground?
               (g=10m/s )
                         2
               3. Find the energy in kWh consumed in 10 hours by four devices of power 500 W
               each.


                                                              1
   1   2