Problem Statement What is the force of gravity on a body of mass 150 kg lying on the surface of the earth ? (Mass of earth = 6 × 10^24 kg; Radius of earth = 6.4 × 10^6 m; G = 6.7 × 10–11 Nm2/kg^2) Solution M1 = mass of the body = 150 kgM2 […]

## Solution to problems – class 9 – Set 1 Q34

Problem Statement Calculate the force of gravitation between two objects of masses 50 kg and 120 kg respectively kept at a distance of 10 m from one another. (Gravitational constant, G = 6.7 × 10 -11 Nm2 /kg^2) Solution M1 = 50 kg M2 = 120 kg Distance = r = 10 m Force of […]

## Solution to problems – class 9 – Set 1 Q31, Q32, Q33

Problem Statement 31) If a box is pushed horizontally on the floor with a force of 10 N and it moves 5 meter along the line of action of the force, then what is the work done by the Gravity or earth’s gravitational pull on that box ? Solution:The angle between the gravity and the […]

## Solution to problems – class 9 – Set 1 Q 27

Problem Statement A bullet leaves a rifle with a muzzle velocity of 600 m/s. While accelerating through the barrel of the rifle, the bullet moves a distance of 0.8 m. Determine the acceleration of the bullet (assume a uniform acceleration). Solution Initial velocity of the bullet U=0 Final velocity of the bullet = muzzle velocity […]