MCQ : Force And Laws Of Motion - 1 - Class 9 MCQ

Always act on the different bodies in opposite directions.

Inertia of an object is the tendency of the object to resist change in motion. The inertia is directly dependent on the mass of the body. 
Inertia resists any change in its state of motion and is of three types:

• Inertia of rest
• Inertia of motion
• Inertia of direction

• While catching a fast moving cricket ball, a fielder in the ground gradually pulls his hand backward with the moving ball, in doing so, the fielder increases the time during which the high velocity of the moving ball decrease to zero.
• This, the acceleration of the ball is decreased and therefore, the impact of catching the fast moving ball is also reduced.

• The question states an accelerated motion of an object along a straight line, this implies a non zero force is acting on the object, which is increasing its velocity and speed.
• However the direction of force is not given so it can’t be determined that it is moving away from the earth, Hence the correct answer is C.

a = slope of graph =  = 2.5 m/s²
F = ma = 5 x 2.5 = 12.5 N
(c) is correct.

"The rate of change of momentum is called force”. “ When a net force acts on a body, it produces acceleration in thr body and will be equal to rate of change of momentum”. Hence , we found that Rate of change of momentum is equal to Force applied on the object .

If no external force applied then acceleration will be zero, so velocity remain conserve. 
Momentum = mass * velocity, if velocity don't Change momentum also not change. 

Newton's second law of motion can be formally stated as follows:- 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.

According to Newton’s second law of motion, also known as the Law of Force and Acceleration, a force upon an object's causes it to accelerate according to the formula:
Net force = mass x acceleration.

So, the acceleration of the object is directly proportional to the force and inversely proportional to the mass.

v = u +at is the only equation of motion present here in the options. Hence, C is the correct answer