1. Newton's first law of motion is also known as:
Answer:
Explanation:
Newton's first law, which states that an object remains at rest or in uniform motion unless acted upon by an external force, is often termed the Law of Inertia.
2. If the net external force on an object is zero, its momentum:
Answer:
Explanation:
According to Newton's first law, if no net force acts on an object, its velocity remains constant, and so does its momentum.
3. The rate of change of momentum is directly proportional to:
Answer:
Explanation:
Newton's second law states that the rate of change of momentum of an object is directly proportional to the force applied and occurs in the direction of the force.
4. An object of mass m moving with velocity v has a momentum p. If the velocity is doubled, the momentum becomes:
Answer:
Explanation:
Momentum is the product of mass and velocity. Doubling the velocity doubles the momentum.
5. Action and reaction forces:
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Explanation:
According to Newton's third law, for every action, there is an equal and opposite reaction. These forces act on different bodies.
6. The measure of inertia is:
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Explanation:
The natural tendency of an object to resist changes in its state of motion is termed inertia. This resistance is directly proportional to the object's mass.
7. If a car takes a sharp turn, the passengers inside tend to move towards the outer edge because of:
Answer:
Explanation:
When a car turns, the passengers experience an outward force due to their inertia, often termed as centrifugal force in a rotating reference frame.
8. A book kept on a table is an example of:
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Explanation:
The book exerts a downward force (action) due to gravity, while the table provides an upward force (reaction) in accordance to Newton's third law.
9. The product of force and time for which it acts on a body is called:
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Explanation:
Impulse is the product of force and the time interval during which it acts and results in a change in momentum.
10. A force of 5N acts on a body for 2 seconds. The impulse imparted to the body is:
Answer:
Explanation:
Impulse = Force x Time = 5N x 2s = 10 Ns.
11. When a body moves in a circular path, it constantly changes its:
Answer:
Explanation:
Even if the body moves with a constant speed, its direction changes, and hence, velocity changes.
12. The frictional force acts:
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Explanation:
Frictional force always opposes the relative motion or tendency of such motion between two surfaces in contact.
13. A car moving with a velocity v is stopped by applying brakes. The distance covered by the car during this process is directly proportional to:
Answer:
Explanation:
Stopping distance or skid distance s = v^2/2gμ, where μ is the coefficient of friction. Thus, it's directly proportional to v^2.
14. A force F acts on a body of mass m and produces an acceleration a. The same force acts on another body of mass 2m, the acceleration produced is:
Answer:
Explanation:
According to Newton's second law, F = ma. When the force is constant, acceleration is inversely proportional to mass.
15. The weight of an object on the moon is:
Answer:
Explanation:
The gravitational acceleration on the moon is about 1/6th of that on Earth, so the weight (which is proportional to gravitational acceleration) is 1/6th.