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Work and energy

A pair of bullocks exerts a force of 140 N on a plough. The field being ploughed is 15 m long. How much work is done in ploughing the length of the field?

10/11/2024

Science

9th

Work and energy

Define 1 J of work.

10/11/2024

Science

9th

Work and energy

Write an expression for the work done when a force is acting on an object in the direction of its displacement.

10/11/2024

Science

9th

Work and energy

When do we say that work is done?

10/11/2024

Science

9th

Gravitation

The volume of a 500 g sealed packet is 350 cm3. Will the packet float or sink in water if the density of water is 1 g cm–3? What will be the mass of the water displaced by this
packet?

10/11/2024

Science

9th

Gravitation

The volume of 50 g of a substance is 20 cm3. If the density of water is 1 g cm–3, will the substance float or sink?

10/11/2024

Science

9th

Gravitation

Why does a block of plastic released under water come up to the surface of water?

10/11/2024

Science

9th

Gravitation

In what direction does the buoyant force on an object immersed in a liquid act?

10/11/2024

Science

9th

Gravitation

A ball thrown up vertically returns to the thrower after 6 s. Find
(a) the velocity with which it was thrown up,
(b) the maximum height it reaches, and
(c) its position after 4 s.

10/11/2024

Science

9th

Gravitation

A stone is allowed to fall from the top of a tower 100 m high and at the same time another stone is projected vertically upwards from the ground with a velocity of 25 m/s. Calculate when and where the two stones will meet.

10/11/2024

Science

9th