Momentum is defined as the product of its mass and velocity.
i.e. Momentum (P) = mass(m) x velocity(v).
Momentum is a measure of the quantity of motion of a body. It is a vector quantity. It has both direction and magnitude. and its direction is same as the direction of velocity. The SI unit of momentum is kg-m/s.
The following is the distance-time table of an object in motion:
|Time in seconds||Distance in meters|
(a) What conclusion can you draw about the acceleration? Is it constant, increasing, decreasing, or zero?
(b) What do you infer about the forces acting on the object?
Justify Newton's first law gives notion (or definition) about force.
Is Newton's second law of motion is consistent with the first law? How?
How Newton's Second law of motion is different from First law?
When two objects act on each other, does action-reaction force pair cancel out each other?
Two objects, each of mass 1.5 kg, are moving in the same straight line but in opposite directions. The velocity of each object is 2.5 m/s before the collision during which they stick together. What will be the velocity of the combined object after collision?
In the following example, try to identify the number of times the velocity of the ball changes:
A football player kicks a football to another player of his team who kicks the football towards the goal. The goalkeeper of the opposite team collects the football and kicks it towards a player of his own team?
Also identify the agent supplying the force in each case.
Why do you fall in the forward direction when a moving bus brakes to a stop and fall backwards when it accelerates from rest?
What are balanced and unbalanced forces?
An object of mass 5 kg is moving with a velocity 4 m/s. A constant force of 20 N acts on the object. What will be the velocity after 3 s.
What is impulse?
The speed-time graph of a car is shown below. The car weighs 1000kg.
(i) Find the distance covered by the in fits two seconds.
(ii) Find how much force is applied by the car brakes in the fifth second so that the car comes to an halt by sixth second.
State why Newton's first law of motion is called law of inertia.
Name the categories of forces based on interaction.
What are non-contact forces? Give examples.
State Newton's third law of motion.
What is collision? What are the types of collision?
An object experiences a net zero external unbalanced force. Is it possible for the object to be travelling with a non-zero velocity? If yes, state the conditions that must be placed on the magnitude and direction of the velocity. If no, provide a reason.
What are contact forces? Give examples
Suppose a ball of mass m is thrown vertically upward with an initial speed v, its speed decreases continuously till it becomes zero. Thereafter, the ball begins to fall downward and attains the speed v again before striking the ground. It implies that the magnitude of initial and final momentums of the ball are same. Yet, it is not an example of conservation of momentum. Explain why ?
Two persons manage to push a motorcar of mass 1200 kg at a uniform velocity along a level road. The same motorcar can be pushed by three persons to produce an acceleration of 0.2m s-2. With what force does each person push the motorcar?
(Assume that all persons push the motorcar with the same muscular effort.)
Are there any limitations to Newton's Laws of motion?
If action is always equal to the reaction, explain how a horse can pull a cart.
Law of conservation of momentum is applicable to an isolated system. What do you mean by an isolated system?