ICS Part 1 Physics English Medium Chapter 3 Online Short Questions Test with Answers

• Ans 1:

Define Impulse ? Show that impulse is equal to change in momentum show that J= P

• Ans 1: Impulse: The product of forces and duration of time in which the force acts is known as impulse.

Define Collision ? Discuss the type of collision?Give example in each case?

• Ans 1: Collision:When two or more than two bodies come so closer to each other that there exists some type of interaction between them in the presence or absence of external forces then such type of interaction is known as collision.
  Type of Collision:There are two type of collision, which are given below.
  Elastic Collision:The Collision in which the momentum and kinetic energy both are conserved is known as elastic collision.
  Examples:
  1. collision of steel balls,
  2. Collision of atoms,
  3. Collision of molecules.

  Inelastic Collision:The Collision in which the momentum is conserved but K.E is not conserved, is known as Inelastic collision. "
  In such type of collision, same type of the K.E is converted into internal energy, sound energy and the work needed to permanently deform the object involed, such as cars ina car crash.
  Example:
  1. Collision between two vehicles
  2. Collision between two mud balls

At what point or points in its path does a projectile have its minimum speed,its maximum speed?

• Ans 1: The speed of the projectile is minimum at the maximum height of projectile. It is because of the reason that; at maximum height the vertical component of velocity becomes zero.
  The speed of the projectile is maximum at the point of projection and also just before it strikes the ground because the vertical component of velocity is maximum at these points.

Discuss the displacement-time Graph?

• Ans 1:

State and explain Newton's second law of motion.

• Ans 1:

What is Ballistic Flight and Ballistic Missile?

• Ans 1: The flight in which projects is given an initial and is then allowed to move freely due to inertia and under the action of gravity is called ballistic flight.
  Ballistic missile is an unpowered and unguided missile.The flight of Ballistic missile is Ballistic flight.

Find on expression for horizontal rang of projectile?

• Ans 1:

Why Newton's first law of motion is known as law of inertia?

• Ans 1: Newton's first law of motion is:
  A body at rest will remain at rest and a body moving with uniform velocity will continue to do so unless acted upon by some unbalanced external force.
  It is based on mass and inertia is the quantitative measure of an object's mass. So Newton's first law of motion is also Known as law of inertia.

Define Force? Define its SI unit ?

• Ans 1: A Force is an agent which stops a moving body try to stop a moving body (or) which moves a stationary body (or) try to move stationary The Product of mass and accelerations known as force
  F = ma
  Unit of force:
  F= ma = kg m/sec²So the unit of force is Newton, Which is define as,
  Force is said to be 1 newton ,if it moves a body of mass 1 kg with acceleration of 1m/sec²,

Define inertial and non-inertial frame of references.

• Ans 1: Inertial Frame of References: The frame of reference in which Newton's first law holds is called inertial frame of reference. It is not an accelerated frame of reference.e.g,, Earth is approximately an inertial frame of reference.
  Non-Inertial Frame of Reference: The frame of reference in which Newton's first law does not hold true is called non-inertial frame of reference.It is an accelerated frame of reference e.g., Space ship etc.

Define momentum and write down its unit.

• Ans 1:

An object is thrown vertically upward.Discuss the sign of acceleration due to gravity, relative to velocity, while the object is in air.

• Ans 1: When the object is thrown vertically upward, it will move against the direction of gravity. The sign of acceleration due to gravity relative to velocity will be taken as negative. When the object is moving downward, the sign of acceleration due to gravity will be positive.

Define the following terms?

Position,

Uniforms

speed,

variable speed

average speed,

Instantaneous speed,

• Ans 1: Position:The location of an object relative to some reference point origin is known as position.
  Speed:The distance between covered by a moving body in one second is known as speed
  Speed = Distance covered /Time
  The speed is a scalar quantity. Its S.I unit is " m/sec" .
  Uniform Speed:A body is said to be moving with uniform speed, if it equal distance in equal intervals of time.
  Variable Speed:A body is said to be moving with variable speed if it covers unequal distance in equal intervals of time.
  Average Speed:The average speed of a moving body can be atained by dividing total distance covered by total time taken
  Instantaneous Speed:The speed of a body at any particular instant of time is known as instantaneous speed.

What is the change in total energy during elastic or inelastic collisions?

• Ans 1: The total energy of the system remains conserved during both type of collisions. But in an inelastic collision, some of the kinetic energy is lost .

What is the difference between uniform and variable velocity?

• Ans 1: Uniform Velocity: A body is said to have a uniform velocity if it covers equal displacement in equal intervals of time.
  
  
  Variable Velocity: A body is said to have a variable velocity if it covers unequal displacements in equal intervals of time.

Write two object?

• Ans 1: Velocity time graph can be used to
  
  1. Calculate the distance covered by the body .
  2. Find the instantaneous acceleration of the body.

• Ans 1:

What is projectile motion? In what direction acceleration is zero in this motion?

• Ans 1: It is the two dimensional motion in which the object moves under constant acceleration due to gravity.
  The acceleration in horizontal direction is zero in projectile motion.

Derive the 3rd equation of motion?

• Ans 1:

Define ballistics flight and ballistic trajectory.

• Ans 1: The flight in which projectile is given an initial push and is then allowed to move freely due to inertia and under the action of gravity is called ballistic flight and the path followed by it is called ballistic trajectory.

Find on expression for horizontal rang of projectile?

• Ans 1:

What is the difference between uniform and variable velocity?

• Ans 1: Uniform Velocity: A body is said to have a uniform velocity if it covers equal displacement in equal intervals of time.
  
  
  Variable Velocity: A body is said to have a variable velocity if it covers unequal displacements in equal intervals of time.

State Newton's third law of motion and give at least two examples.

• Ans 1: It states that every action has a reaction which is equal in magnitude but opposite in direction.An ideal elastic collision and propulsion of a rocket are two good examples of third law of motion.

What is ballistic missile? Define ballistic trajectory.

• Ans 1: The missile in which it is given an initial push and is then allowed to move freely due to inertia and under the action of gravity is called ballistic and the path followed by such a projectile is called ballistic trajectory.

State and explain Newton's second law of motion.

• Ans 1:

Define the following terms?

Velocity,

Uniform Velocity,

Variable Velocity,

Average Velocity.

Instantaneous Velocity.

• Ans 1: Velocity:The distance between covered by a body in one second along a particular direction is known as velocity.
  V = S/t velocity is a vector quantity. its standard unit is "m/sec
  Uniform Velocity:A body is said to be moving with uniform velocity, if it covers equal displacement in equal intervals of time .
  Variable Velocity:A body is said to be moving with variable velocity, if it covers unequal displacement in equal intervals of time.
  Average Velocity:The average velocity can be obtained by dividing total displacement by total time taken.
  Average velocity = Total Displacement /Total time taken
  V = S/T
  Instantaneous Velocity:The velocity of a body at any particular instant of time is known as instantaneous velocity.

Define the following terms?

Acceleration

Uniform Acceleration

Variable Acceleration

Radical Acceleration

Linear Acceleration

Positive Acceleration

Negative Acceleration

Instantaneous Acceleration

• Ans 1: Acceleration:The rate of change of velocity is known as acceleration.
  Mathematically, we have
  Acceleration = v/t It is a vector quantity. It SI unit m/sec²
  Dimensions of acceleration:We know that
  V= Displacement / time = m/sec= Length / Time
  V=[L T^-1]
  Dimensions of acceleration:We Known that
  a = Velocity/time = m/sec . sec = m/sec^-2
  a = Length/time² a = [L T^-2]
  Uniform Acceleration:A body is said to be moving with the uniform acceleration if equal change occurs in velocity in equal intervals of time.
  Variable Acceleration:A body is said to be moving with variable Acceleration if unequal change occurs in velocity in equal intervals intervals of time.
  Linear Acceleration:The acceleration which is produced due to change in magnitude of velocity is known as linear acceleration.
  Radical Acceleration:The acceleration which is produced due to change indirection of velocity is known as radical acceleration.
  Positive Acceleration:The acceleration is said to be positive if the magnitude of velocity increases with respect to time.
  Negative Acceleration:The acceleration will be magnitude of velocity decreases with respect to time.
  InstantaneousAcceleration:The acceleration of a body at any particular instant of time is known as instantaneous acceleration.

Derive an equation for the position vector of projectile?

• Ans 1:

What is projectile motion? In what direction acceleration is zero in this motion?

• Ans 1: It is the two dimensional motion in which the object moves under constant acceleration due to gravity.
  The acceleration in horizontal direction is zero in projectile motion.

Write any two properties of inertial frame of reference.

• Ans 1:
  1. A non-accelerated frame of reference is an inertial frame of reference.
  2. Newton's 1st law of motion holds good in an inertial frame of reference.

Define maximum height of projectile? Derive a mathematical expression for maximum height of projectile ?

• Ans 1:

State and explain Newton's second law of motion.

• Ans 1:

Why a safety helmet of a motor cycle's is padded?

• Ans 1: A motor cycle's safety helmet is padded so as to extend the time of collision to prevent serious injury.

Can the velocity of an object reverse the direction when acceleration is constant? If so, given an example.

• Ans 1: Yes, the velocity of a body can reverse its direction with constant acceleration For example, when a body is thrown vertically upward under the action of gravity, the velocity of the object will go on decreasing because force of gravity is acting downward.
  When the object reaches the maximum height , its velocity becomes zero, and then the object reverses its direction of motion and start moving vertically downward.During the whole process, the magnitude of the acceleration due to gravity remains constant.

What is the change in total energy during elastic or inelastic collisions?

• Ans 1: The total energy of the system remains conserved during both type of collisions. But in an inelastic collision, some of the kinetic energy is lost .

What is the effect on the speed of a fighter plane chasing another when it opens the fire? What happens to the speed of purdued plane when it returns the fire?

• Ans 1: When the fighter plane opens fire, its momentum will be in back direction due to reaction force in backwards direction and therefore its speed will decrease.
  When the pursued plane opens fire in the backward direction, the momentum will act on the plane in forward direction due to reaction and therefore its speed will increase.

Derive the 3rd equation of motion?

• Ans 1:

Motion with constant velocity is a special case of motion with constant acceleration.Is this statement true?

• Ans 1: Yes, this statement is true. When a body moves with constant velocity in the straight line, its acceleration is zero.Hence,The acceleration of the body will always remain constant during such motion.As the zero is a constant quantity, therefore this is a special case of motion.

Define Force? Define its SI unit ?

• Ans 1: A Force is an agent which stops a moving body try to stop a moving body (or) which moves a stationary body (or) try to move stationary The Product of mass and accelerations known as force
  F = ma
  Unit of force:
  F= ma = kg m/sec²So the unit of force is Newton, Which is define as,
  Force is said to be 1 newton ,if it moves a body of mass 1 kg with acceleration of 1m/sec²,

Write two object?

• Ans 1: Velocity time graph can be used to
  
  1. Calculate the distance covered by the body .
  2. Find the instantaneous acceleration of the body.

At what point or points in its path does a projectile have its minimum speed,its maximum speed?

• Ans 1: The speed of the projectile is minimum at the maximum height of projectile. It is because of the reason that; at maximum height the vertical component of velocity becomes zero.
  The speed of the projectile is maximum at the point of projection and also just before it strikes the ground because the vertical component of velocity is maximum at these points.

What is ballistic missile? Define ballistic trajectory.

• Ans 1: The missile in which it is given an initial push and is then allowed to move freely due to inertia and under the action of gravity is called ballistic and the path followed by such a projectile is called ballistic trajectory.

Differentiate between distance and displacement.

• Ans 1:
  

Discuss the momentum changes produced by explosive forces ?

• Ans 1: There are many cases where momentum changes are produced by explosive forces within an isolated system. It can be explain with the help of following Example:
  When a sheel explodes in mind-air its fragment fly apart in different direction. the various forces which occur in the explosion have zero resultant, because they cancel the effect of each other. so the total moments of the fragments is equal to the initial momentum of the sheel.

Define total of flight. Derive a mathematical expression for it ?

• Ans 1: The term taken by projectile from point of projection to the striking point is known as total time of flight.

Define maximum height of projectile? Derive a mathematical expression for maximum height of projectile ?

• Ans 1:

Find a relation for magnitude of velocity of projectile and direction of projectile?

• Ans 1:

State and explain Newton's second law of motion.

• Ans 1:

What is the effect on the speed of a fighter plane chasing another when it opens the fire? What happens to the speed of purdued plane when it returns the fire?

• Ans 1: When the fighter plane opens fire, its momentum will be in back direction due to reaction force in backwards direction and therefore its speed will decrease.
  When the pursued plane opens fire in the backward direction, the momentum will act on the plane in forward direction due to reaction and therefore its speed will increase.

Define the following terms?

Acceleration

Uniform Acceleration

Variable Acceleration

Radical Acceleration

Linear Acceleration

Positive Acceleration

Negative Acceleration

Instantaneous Acceleration

• Ans 1: Acceleration:The rate of change of velocity is known as acceleration.
  Mathematically, we have
  Acceleration = v/t It is a vector quantity. It SI unit m/sec²
  Dimensions of acceleration:We know that
  V= Displacement / time = m/sec= Length / Time
  V=[L T^-1]
  Dimensions of acceleration:We Known that
  a = Velocity/time = m/sec . sec = m/sec^-2
  a = Length/time² a = [L T^-2]
  Uniform Acceleration:A body is said to be moving with the uniform acceleration if equal change occurs in velocity in equal intervals of time.
  Variable Acceleration:A body is said to be moving with variable Acceleration if unequal change occurs in velocity in equal intervals intervals of time.
  Linear Acceleration:The acceleration which is produced due to change in magnitude of velocity is known as linear acceleration.
  Radical Acceleration:The acceleration which is produced due to change indirection of velocity is known as radical acceleration.
  Positive Acceleration:The acceleration is said to be positive if the magnitude of velocity increases with respect to time.
  Negative Acceleration:The acceleration will be magnitude of velocity decreases with respect to time.
  InstantaneousAcceleration:The acceleration of a body at any particular instant of time is known as instantaneous acceleration.

An object is thrown vertically upward.Discuss the sign of acceleration due to gravity, relative to velocity, while the object is in air.

• Ans 1: When the object is thrown vertically upward, it will move against the direction of gravity. The sign of acceleration due to gravity relative to velocity will be taken as negative. When the object is moving downward, the sign of acceleration due to gravity will be positive.

Name the quantities which can be calculated from velocity-time graph and these can be calculated ?

• Ans 1: Distance moved by the body and its acceleration can be calculated by the velocity-time graph.
  Area under the velocity time graph line is equal to the distance covered by the body. Slope of the tangent at any point gives the instantaneous acceleration at that point.

Write any two properties of inertial frame of reference.

• Ans 1:
  1. A non-accelerated frame of reference is an inertial frame of reference.
  2. Newton's 1st law of motion holds good in an inertial frame of reference.

Show that for the same initial speed and some range of projectile there are two mutually complementary angles of projection ?

• Ans 1:

Define elastic and inelastic collisions.

• Ans 1: Elastic collisions: A collision in which the K.E. Of the system is conserved is called elastic collision.
  Inelastic collisions: A collision in which the K.E.of the system is not conserved is called inelastic collision.

What is projectile motion? In what direction acceleration is zero in this motion?

• Ans 1: It is the two dimensional motion in which the object moves under constant acceleration due to gravity.
  The acceleration in horizontal direction is zero in projectile motion.

What is the effect on the speed of a fighter plane chasing another when it opens the fire? What happens to the speed of purdued plane when it returns the fire?

• Ans 1: When the fighter plane opens fire, its momentum will be in back direction due to reaction force in backwards direction and therefore its speed will decrease.
  When the pursued plane opens fire in the backward direction, the momentum will act on the plane in forward direction due to reaction and therefore its speed will increase.

Define maximum height of projectile? Derive a mathematical expression for maximum height of projectile ?

• Ans 1:

Why ballistic missiles are not useful for long ranges?

• Ans 1: Ballistic missiles are unpowered and unguided missiles. For long ranges, air friction is not negligible and some times the force of air friction is more than gravity. It affects both horizontal as well as vertical motions of the missile.