Motilal nehru public school jind class 9th dpp 1 Newton's law of motion all level question

please download in pdf 

click here 

👇👇👇👇👇👇👇👇

https://knowingonline.in/2020/07/27/class-ix-newtons-law-of-motion/

Question 1.
Deduce Newton’s first law from the second law.

Question 2.
When small boy is trying to push a heavy stone, mention various forces acting on the stone.

Question 3.
Describe in brief an activity to illustrate the property of inertia of rest.

Question 3.
Describe in brief an activity to illustrate the property of inertia of rest.

Question 4.
Give few examples of Newton’s third law of motion.

Question 5.

Two friends on roller-skates are standing 5 m apart facing each other. One of them throws a ball of 2 kg towards the other, who catches it. How will this activity affect the position of the two? Explain your answer. [NCERT Exemplar]

Question 6.
Why does an athlete puts some sands or cushion on the ground while high jumping?

Question 6.
Why does an athlete puts some sands or cushion on the ground while high jumping?

Question 7.
Describe balanced forces with the help of two examples.

Question 8.
Why do the driver and the person seated in front seat need a seat belt?

 

Numericals
Question 1.
A bullet of 10 g strikes a sand bag at a speed of 10³ ms^-1 and gets embedded after travelling 5 cm. Calculate
(i) the resistive force exerted by the sand on the bullet.
(ii) the time taken by the bullet to come to rest. [NCERT Exemplar]

Question 2.
A body of mass 300 g kept at rest breaks into two parts due to internal forces. One part of mass 200 g is found to move at a speed of 12 m/s towards the east. What will be the velocity of the other part?

Question 3.
A force of 5 N produces an acceleration of 8 ms^-2 on a mass m₁ and an acceleration of 24 ms^-2 on a mass m₂. What acceleration would the same force provide if both the masses are tied together? [NCERT Exemplar]

Question 4.
The velocity-time graph of a ball moving on the surface of floor is shown in the figure. Calculate the force acting on the ball, if mass of the ball is 100 g.

Question 5.
A bullet of mass 4 g when fired with a velocity of 50 ms^-1, can enter a wall up to a depth of 10 cm. How much will be the average resistances offered by the wall?

Question 6.
What is the acceleration produced by a force of 12 newton exerted on an object of mass 3 kg?

Question 8.
An iron sphere of mass 1 kg is dropped from a height of 10 m. If the acceleration of sphere is 9.8 ms^-2, calculate the momentum transferred to the ground by the ball.
Question 9.
A bullet of mass 0.02 kg is fired from a gun weighing 7.5 kg. If the initial velocity of the bullet is 200 m/s, calculate the speed with which the gun recoils

Question 10.
The velocity-time graph of a ball moving on the surface of a floor is shown in the figure. Find the force acting on the ball if the mass of the ball is 50 g.

Question 11.
A man throws a ball of mass 0.4 kg vertically upwards with a velocity of 10 m/s. What will be its initial momentum? What would be its momentum at the highest point of its reach?

Question 12.
Which would require a greater force—accelerating a 2 kg mass at 5 ms^-2 or a 4 kg mass at 2 ms^-2 ?

Question 13.
A bullet of mass 20 g is horizontally fired with a horizontal velocity 150 ms^-1 from a pistol of mass 2 kg. What is the recoil velocity of the pistol?

Question 14.
A boy of mass 40 kg jumps with a horizontal velocity of 5 ms^-1 onto a stationary cart with frictionless wheels. The mass of the cart is 3 kg. What is his velocity as the cart starts moving? Assume that there is no external unbalanced force working in horizontal direction.

 

 

 

 

CBSE LEVEL QUESTION

Question 1.
Name the scientist who proved for the first time that objects move with constant speed when no force acts on them.

Question 2.
Why do bicycles begin to slow down when we stop pedalling?

Question 3.
Which law of motion gives the measure of force?

Question 3.
Which law of motion gives the measure of force?

Question 4.
Write the C.G.S unit of force.

Question 5.
Can every force produce motion in every object?

Question 6.
When a force is applied to a body, what are the two essential effects it can produce?