The table indicates details regarding lifting of bricks by three persons A, B and C. Mass of a brick is 20 Kg. (g = 10 m/s²)

1. Find out the value of (x) and (y) in the table.

2. Who among these have done equal work ?

3. Who among the three has more power ?

Identify the relation in the first set and fill up the second accordingly -

1 HP : 746 W         ::              1 KW : .......                    

Sun is the ultimate source of energy.

1. Write the name of any two rays from the Sun.

2. Write down two situation where solar energy is made use of. 

If an object is falling from a height of 50 m and reaches at a distance of 30 m above the ground then,

a)It has only potential energy

b)It has only kinetic energy

c)Has keinetic energy and potential energy

d) Its potential energy decreases and kinetic energy increases

e) Its potential energy increases and kinetic energy decreases         

Identify the odd one on the basis of energy level -

a) braced bow

b) stretched rubber band

c) pressed spring

d) running car                                                      

Potential energy and Kinetic energy are two forms of Mechanical energy

1. Which form of energy is obtained due to motion ?

2. In which situation a stone of mass 4 Kg will possess more energy –

   when placed at a height of 2 m, or

   when travelling at a velocity of 2 m/s²

Identify the odd one on the basis of unit -

work , power , kinetic energy , potential energy

Find out the relation of the first set and fill up the second set accordingly

potential energy : mgh

kinetic energy : ............

Fill up the table.

Work : F X s

Power : ..........

Find out the relation of the first set and fill up the second set -

Work : Joule                                                                     

Power : ........

1. What are the factors that influence work done ?

2. Calculate the work done if an object has a displacement of 2 m when  applying a force of 10 N on it.