Advertisements
Advertisements
Question
Give a scientific reason.
When an object falls freely to the ground, its acceleration is uniform.
Advertisements
Solution
When an object falls freely to the ground, it is under the effect of a constant force known as the force of gravity. No other forces act on it. Hence, from Newton's second law of motion, we can say that this constant force of gravity accelerates the freely falling object uniformly. This uniform acceleration is known as acceleration due to gravity which acts towards the centre and is denoted by g.
APPEARS IN
RELATED QUESTIONS
An object of mass 16 kg is moving with an acceleration of 3 m/s2. Calculate the applied force. If the same force is applied to an object of mass 24 kg, how much will be the acceleration?
A train starts from rest and accelerates uniformly at a rate of 2 m s−2 for 10 s. It then maintains a constant speed for 200 s. The brakes are then applied and the train is uniformly retarded and comes to rest in 50 s. Find
- The maximum velocity reached,
- The retardation in the last 50 s,
- The total distance travelled,
- The average velocity of the train.
From the diagram given below, calculate acceleration.
From the velocity – time graph given below, calculate deceleration in region BC.
A racing car, initially at rest, picks up a velocity of 180 kmh−1 in 4.5 s. Calculate
- acceleration
- distance covered by the car.
The acceleration of a moving body is constant in magnitude and direction. Must the path of the body be a straight line?
If not, given an example.
A body falls towards the earth. Does it have positive or negative acceleration?
A car traveling at 60 km/h, stops on applying brakes in 10 seconds. What is its acceleration?
State if the following situation is possible:
A body moving horizontally with an acceleration in vertical direction.
State if the following situation is possible:
A body moving with a constant velocity in an accelerated motion.
Is it possible for an accelerating body to have constant speed?
A car accelerates uniformly from a velocity of 18 km/h to 36 km/h in 15 min. What is its acceleration?
If the velocity of a body does not change, then its acceleration is ______.
A boy throws a ball up and catches it when the ball falls back. In which part of the motion the ball is accelerating?
Acceleration is defined as the rate of change of ______.
Assertion: A positive acceleration of a body can be associated with the slowing down of the body.
Reason: Acceleration is a vector.
When a body is said to be in
- uniform acceleration
- non–uniform acceleration?
