Advertisements
Advertisements
प्रश्न
A person drops a coin. Describe the path of the coin as seen by the person if he is in
- a car moving at constant velocity and
- in a free falling elevator.
Advertisements
उत्तर
When the person drops the coin, the path of the coin as seen by the person is:
(a)
- When a person drops a coin inside a car moving at constant velocity, the coin appears to fall straight down from the person’s point of view.
- This is because both the person and the coin are moving forward with the same velocity as the car.
- There is no additional force acting on the coin in the horizontal direction, so the coin retains its forward motion and lands directly below the point from which it was dropped.
- This situation reflects the principle of relative motion and supports Newton’s first law an object in motion continues in motion unless acted upon by an external force.
(b)
- In a free falling elevator, both the person and the coin are accelerating downward at the same rate due to gravity.
- When the person drops the coin, from their point of view, it appears to hover, float in the air, or fall very slowly.
- The person and the coin are both in free fall together, so there is no relative acceleration.
- This provides the sensation of weightlessness, similar to what astronauts experience in orbit.
APPEARS IN
संबंधित प्रश्न
An aircraft executes a horizontal loop at a speed of 720 km/h with its wings banked at 15°. What is the radius of the loop?
The figure shows the displacement of a particle going along the X-axis as a function of time. The force acting on the particle is zero in the region

(a) AB
(b) BC
(c) CD
(d) DE
A block of mass 0.2 kg is suspended from the ceiling by a light string. A second block of mass 0.3 kg is suspended from the first block by another string. Find the tensions in the two strings. Take g = 10 m/s2.
Find the reading of the spring balance shown in the following figure. The elevator is going up with an acceleration g/10, the pulley and the string are light and the pulley is smooth.

The force of buoyancy exerted by the atmosphere on a balloon is B in the upward direction and remains constant. The force of air resistance on the balloon acts opposite the direction of velocity and is proportional to it. The balloon carries a mass M and is found to fall to the earth's surface with a constant velocity v. How much mass should be removed from the balloon so that it may rise with a constant velocity v?
Consider the situation shown in the following figure All the surfaces are frictionless and the string and the pulley are light. Find the magnitude of acceleration of the two blocks.

A constant force F = m2g/2 is applied on the block of mass m1 as shown in the following figure. The string and the pulley are light and the surface of the table is smooth. Find the acceleration of m1.

Calculate the tension in the string shown in the following figure. The pulley and the string are light and all the surfaces are frictionless. Take g = 10 m/s2.

In the following figure shows a man of mass 60 kg standing on a light weighing machine kept in a box of mass 30 kg. The box is hanging from a pulley fixed to the ceiling by a light rope, the other end of which is held by the man himself. If the man manages to keep the box at rest, what is the weight recorded on the machine? What force should he exert on the rope to record his correct weight on the machine?

Define linear momentum and state its S.I. unit.
The correct form of Newton's second law is :
The linear momentum of a body of mass m moving with velocity v is :
A force of 10 N acts on a body of mass 2 kg for 3 s, initially at rest. Calculate : Change in momentum of the body.
A force acts for 10 s on a stationary body of mass 100 kg, after which the force ceases to act. The body moves through a distance of 100 m in the next 5 s. Calculate : The magnitude of the force
A body of mass 200 g is moving with a velocity of 5 ms−1. If the velocity of the body changes to 17 ms−1, calculate the change in linear momentum of the body.
Name the physical entity used for quantifying the motion of a body.
State Newton's second law of motion.
A body of mass 400 g is resting on a frictionless table. Find the acceleration of the body when acted upon by a force of 0.02 N.
Use Newton's second law to explain the following:
We always prefer to land on sand instead of hard floor while taking a high jump.
A woman throws an object of mass 500 g with a speed of 25 ms1.
- What is the impulse imparted to the object?
- If the object hits a wall and rebounds with half the original speed, what is the change in momentum of the object?
