The ultimate source of our energy is
sun
coal
wind
plants
The force which pulls a body towards the earth is called
friction
gravity
tension
collision
Machines cannot do the following
machines make work easy
machine increase the speed of doing work
machines change the direction of force
machines produce energy
While playing football, the ball is passed from player to player at different speeds. It is possible because of
players expertise
the ground
gravitational pull
force
The capacity to do work is called
energy
machine
movement
If we apply force on a moving object in the same direction, the speed of the object
decreases
remains the same
increases
increases or decreases
Which one of the following statements is NOT true?
Friction makes a moving object slow down and stop
Friction between two surfaces will make them hot
Friction also enables an object to stay in a stationary position
Friction decreases if roughness of an object increases
Which one of the following energies can be replenished?
Solar energy
Wind energy
Water energy
All of the above
Which one of the following cannot be done by using muscular force?
Changing the direction of a moving body
Stopping a moving body
Changing or decreasing the speed of a body
Increasing or decreasing the speed of a body
A goal keeper stopped a moving ball by applying force. What inference can you draw this example ?
The ball was slow
Force applied by goal keeper is more than the force with the ball was moving
Force can stop a moving object
The ball stopped due to frictional force