Engineering Questions with Answers - Multiple Choice Questions

# MCQs on Impulse Momentum Equation

1 - Question

When a cricket bat hits a cricket ball, impulse is applied on the_________
a) Bat
b) Ball
c) Bat and ball
d) No impulse is applied

b
Explanation: Time passes as force is applied on an object. The bat applies the force on the ball for a short period of time. By this way, we can say in accordance to the Newton’s third law forces come in pairs. So, the ball also applies a force on the bat, therefore it has an impulse applied to it.

2 - Question

Momentum is a ______ quantity
a) Scalar
b) Vector
c) Infinite
d) Zero

b
Explanation: Momentum is a vector quantity as it has both size and direction. Size of the momentum is equal to the mass of the object into the size of the objects velocity. The direction of objects velocity is the same as the direction of the momentum.

3 - Question

The equation for impulse is_______
a) F∆t=m∆v
b) F∆t=mu
c) F∆t=mT
d) F∆t=mRT

a
Explanation: Impulse is equal to the net force times the length of time over which the force is applied on the body of the fluid. On the right hand side, we have the change in momentum. Thus, option ‘a’ is the most suitable one.

4 - Question

What is the SI unit of impulse?
a) N/m
b) N/m2
c) N.s
d) Kg.m

c
Explanation: The SI unit of impulse is Newton second. It is given by the linear momentum due to the vector change. This produces an impulse in the same direction with respect to a given time.

5 - Question

What is the SI unit of momentum?
a) kgm/s
b) kgm/s2
c) kgm/s3
d) kg.m2

a
Explanation: The SI unit of momentum is given by the product of the units of mass and velocity. In SI units, (mass is in kg) and (velocity is in m/s). As we know that momentum is mass times velocity. The unit turns out to be kgm/s.

6 - Question

Change in momentum of an object is equal to the_______
a) Internal Energy
b) Entropy
c) Impulse
d) Enthalpy

c
Explanation: The mass is distributed over two velocities. According to the Newton’s second law, the change in momentum is equal to the impulse so produced. Since, momentum is a quantity that describes an object’s resistance to stopping. It is equated with its impulse.

7 - Question

What is the unit of specific impulse?
a) m/s
b) m2/s
c) m3/s
d) m/s2

a
Explanation: Specific impulse is equal to the exhaust velocity of the fluid. Since, the unit of exhaust velocity is m/s, the unit of specific impulse is also the same. It is used to measure the efficacy of rocket propellants.

8 - Question

What is the formula to find specific impulse?
a) Jsp=m/v
b) Jsp= J/m
c) Jsp=T/m
d) Jsp=J/q

b
Explanation: Specific impulse is defined as impulse per weight. It can also be defined as thrust per weight of a flow rate. It is equal to the exhaust velocity divided by acceleration due to gravity. (SI Unit: m/s)

9 - Question

Angular momentum is a _______ quantity
a) Scalar
b) Vector
c) Infinite
d) Finite

b
Explanation: Angular momentum is a vector quantity as it has both size and direction. Size of the momentum is equal to the mass of the object into the size of the object’s velocity. The direction of objects velocity is the same as the direction of the momentum.

10 - Question

Angular momentum is proportional to __________
a) Inertia and angular speed
b) Mass and angular speed
c) Angular speed and volume
d) Rate of change of angular speed