# Laws of Motion - Online Test

Q1. force is required
Explaination / Solution:

force is required to start a stationary object and to stop a moving object due to inertia. Inertia is a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force. This is also called law of inertia or newton's first law of motion

Q2. According to first law of motion
Explaination / Solution:

If net force act on a body then acceleration of the body will also be zero.Hence velocity will not be changed i.e. it continues in its existing state of rest or uniform motion in a straight line.

Q3. Inertia refers to
Explaination / Solution:

Inertia is the resistance of any physical object to any change in its state of motion; this includes changes to its speed, direction, or state of rest. It is the tendency of objects to keep moving in a straight line at constant velocity. Inertia is a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force.

Q4. Momentum of a body is
Explaination / Solution:

p⃗ =mv⃗
Q5. According to Newton's second law of motion
Explaination / Solution:

If mass does not change then acceleration of a particle is dependent on the forces acting upon the particle and the particle's mass. For a given particle, if the net force is increased, the acceleration is increased. For a given net force, the more mass a particle has, the less acceleration it has.

$\mathbf{F}=m\mathbf{a}=m\frac{\mathrm{d}\mathbf{v}}{\mathrm{d}t}=\frac{\mathrm{d}\left(m\mathbf{v}\right)}{\mathrm{d}t}=\frac{\mathrm{d}\mathbf{p}}{\mathrm{d}t}.$

hence the rate of change of momentum of a body is directly proportional to the applied force

Q6. Force is a
Explaination / Solution:

Newton's second law of motion gives the quantitative definition of force. The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object

Q7. Second law in terms of momentum p and mass m is
Explaination / Solution:

Applied force is directly proportional to rate of change of momentum.
Q8. The second law of motion is a vector law. It is equivalent toFx=max,Fy=may,Fz=maz
Explaination / Solution:
No Explaination.

Q9. The force acting on a freely falling body in terms of mass m and acceleration due to gravity g is
Explaination / Solution:

according to newton's second law of motion F = ma here acceleration is due to gravity and is equal to g. So that for a freely falling body F = mg

Q10. Impulse is
Explaination / Solution:

A resultant force causes acceleration and a change in the velocity of the body for as long as it acts.The change in momentum is equal to the product of the average force and duration. Conversely, a small force applied for a long time produces the same change in momentum, the same impulse, as a larger force applied for a short time interval.

Impulse J is

The impulse is the integral of the resultant force (F) with respect to time