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प्रश्न
Give a scientific reason.
When an object falls freely to the ground, its acceleration is uniform.
उत्तर
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.
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संबंधित प्रश्न
Define acceleration. State its unit.
The unit of retardation is ____________
A toy car initially moving with uniform velocity of 18 km h-1 comes to a stop in 2 s. Find the retardation of the car in S.I. units.
The velocity-time graph for a uniformly retarded body is a straight line inclined to the time axis with an obtuse angle. How is retardation calculated from the velocity-time graph?
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
(i) The maximum velocity reached,
(ii) The retardation in the last 50 s,
(iii) The total distance travelled,
(iv) The average velocity of the train.
A car travels with uniform velocity of 25 m s-1 for 5 s. The brakes are then applied and the car is uniformly retarded and comes to rest in further 10 s. Find:
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- Retardation and
- The distance travelled by car after applying the brakes.
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Write the SI unit of acceleration and retardation.
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State if the following situation is possible:
A body moving with a constant velocity in an accelerated motion.
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7200 km/h2 into m/s2
Convert the following acceleration:
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From the given v-t graph it can be inferred that an object is
What do you understand about negative acceleration?
