The spring balance has a scale that reads from zero to `30 kg`. The length of the scale is` 30cm`. If the period of oscillation is `1 sec`. Calculate mass of the body attached to the spring.

The spring has a scale that reads from zero to 30 kg . The length of the scale is 30cm . Calculate the force constant K.

Weighing a stone of lower mass and another of higher mass by using a spring balance. [Mass of a body is the amount of matter contained in it] On the basis of these observations, find out the factor that influences the force of attraction from the earth.

A convex lens produces an inverted image of size 1.4cm The size of object is 0.7cm. If the object is at distance 30 cm from the lens. Calculate focal length of the lens

An external force is always required to brake the inertia of a body which is either in the state of rest or state of uniform motion. A boy holding a spring balance in his hand suspend a mass 2kg from it. If the balance slips from his hand and falls down, find the reading of the balance while it is in the air.

A graph paper is situated on a board as shown in figure. Near the graph paper a spring is placed. A pencil attached to the end of the spring as shown in figure. The pencil is free to move on the graph paper. A stone of mass 50g m is placed 1 m above the spring. [Spring constant k= 98N/m ]. What will happen to the length of mark if spring having smaller spring constant is used? Justify.