The potential energy of a freely falling object decreases
progressively. Does this violate the law of conservation of
energy? Why?
A certain household has consumed 250 units of energy during
a month. How much energy is this in joules?
3. In case of negative work the angle between the force and displacement is
(a) 00
(b) 450
(c) 900
(d ) 1800
An iron sphere of mass 10 kg has the same diameter as an aluminium sphere of mass is 3.5 kg. Both spheres are dropped simultaneously from a tower. When they are 10 m above the ground, they have the same
(a) acceleration
(b) momenta
(c) potential energy
(d) kinetic energy
A girl is carrying a school bag of 3 kg mass on her back and moves 200 m on a levelled road. The work done against the gravitational force will be (g =10 m s–2)
(a) 6 ×103 J
(b) 6 J
(c) 0.6 J
(d) zero
Which one of the following is not the unit of energy?
(a) joule
(b) newton metre
(c) kilowatt
(d) kilowatt-hour
Water stored in a dam possesses
(a) no energy
(b) electrical energy
(c) kinetic energy
(d) potential energy
Can any object have mechanical energy even if its momentum is zero? Explain.
If an electric iron of 1200 W is used for 30 minutes everyday, find electric energy consumed in the month of Apri
Draw the graph for uniform and non uniform motion