Forum

Work and Energy

The work done on an object does not depend upon the
(a) displacement
(b) force applied
(c) angle between force and displacement
(d) initial velocity of the object

05/11/2024

Science

9th

Work and Energy

Which one of the following is not the unit of energy?
(a) joule
(b) newton metre
(c) kilowatt
(d) kilowatt hour

05/11/2024

Science

9th

Work and Energy

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

05/11/2024

Science

9th

Work and Energy

In case of negative work the angle between the force and displacement is
(a) 00 (b) 450 (c) 900 (d ) 1800

05/11/2024

Science

9th

Work and Energy

A car is accelerated on a levelled road and attains a velocity 4 times of its
initial velocity. In this process the potential energy of the car
(a) does not change
(b) becomes twice to that of initial
(c) becomes 4 times that of initial
(d) becomes 16 times that of initial

05/11/2024

Science

9th

Work and Energy

When a body falls freely towards the earth, then its total energy
(a) increases
(b) decreases
(c) remains constant
(d) first increases and then decreases

05/11/2024

Science

9th

Gravitation

How does the force of attraction between the two bodies depend upon their
masses and distance between them? A student thought that two bricks
tied together would fall faster than a single one under the action of gravity.
Do you agree with his hypothesis or not? Comment.

05/11/2024

Science

9th

Gravitation

How does the weight of an object vary with respect to mass and radius of
the earth. In a hypothetical case, if the diameter of the earth becomes half
of its present value and its mass becomes four times of its present value,
then how would the weight of any object on the surface of the earth be
affected?

05/11/2024

Science

9th

Gravitation

The earth is acted upon by gravitation of Sun, even though it does not fall into the Sun. Why?

05/11/2024

Science

9th

Gravitation

Calculate the average density of the earth in terms of g, G and R

05/11/2024

Science

9th