Kinetic Energy and Momentum - NEET Physics Chapterwise MCQs & PYQs

NEET Kinetic Energy and Momentum MCQs & PYQs

Practice NEET Kinetic Energy and Momentum Questions

Question 1:

easy

A 1 kg mass has a kinetic energy of 1 joule when its speed is :

Kinetic Energy K = ½mv²

So, 1J = ½(1)v² so, v= √2 m/s= 1.414 m/s

💬 Discuss this Question

Question 2:

easy

When the velocity of a body is doubled :

Momentum of an object is P = m.v

So, when velocity is doubled momentum also doubles

💬 Discuss this Question

Question 3:

moderate

Two masses of 1 g and 4 g are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is

Kinetic Energy is given by K = ½mv² and Momentum is P=m.v, relation between kinetic energy and momentum is

K= P²/2m so P=√(2mK)

So P1/P2= √(m1)/√(m2)= √1/√4 = 1:2

💬 Discuss this Question

Question 4:

moderate

If the kinetic energy of a body is increased by 300%, its momentum will increase by :

Relation between Kinetic Energy and Momentum is

P = √(2mK)

When kinetic energy is increased by 300 % it becomes 4K so new momentum is

P1= √(2m.4K) =2P

💬 Discuss this Question

Question 5:

moderate

If the kinetic energy of a body is increased by 3%, its momentum will increase by :

K = P²/2m so,

∇K/K=2∇P/P

Solving We get , ∇P/P = 1.5%

💬 Discuss this Question

Question 7:

easy

If the kinetic energy of a body increases by 800%, its momentum increases by

The momentum \(P\) is related to kinetic energy \(K\) by \(P = \sqrt{2mK}\). An 800% increase means the new kinetic energy is \(K' = 9K\). Thus, the new momentum is \(P' = \sqrt{9} P = 3P\), representing an increase of 200%.

💬 Discuss this Question

Question 8:

easy

Two masses \( 4m \) and \( 9m \) move with equal kinetic energy. The ratio of the magnitude of their momenta is:

Since kinetic energy \( K \) is the same for both masses, the momentum is proportional to the square root of the mass, \( p = \sqrt{2mK} \). Thus, the ratio of their momenta is \( \frac{p_1}{p_2} = \sqrt{\frac{4m}{9m}} = \frac{2}{3} \).

💬 Discuss this Question

Question 9:

easy

Two masses \(1\text{ g}\) and \(9\text{ g}\) are moving with equal kinetic energies. The ratio of the magnitudes of their respective linear momenta is

Since linear momentum \(p = \sqrt{2mK}\) and kinetic energy \(K\) is constant, \(p \propto \sqrt{m}\). Therefore, the ratio of momenta is \(\frac{p_1}{p_2} = \sqrt{\frac{1}{9}} = 1:3\).

💬 Discuss this Question

Question 10:

easy

Assertion (A): A body cannot have kinetic energy without having linear momentum but it can have momentum without having mechanical energy.

Reason (R): Linear momentum and energy have same dimensions.

 

Assertion (A) is false:

If a body has linear momentum (\(p \neq 0\)), it must have velocity (\(v \neq 0\)), which implies it must also have kinetic energy (\(KE = \frac{1}{2}mv^2 \neq 0\)). Since kinetic energy is a component of mechanical energy, it cannot have momentum without mechanical energy.

Reason (R) is false: Linear momentum has dimensions \(MLT^{-1}\) while energy has dimensions \(ML^2T^{-2}\), which are different.

💬 Discuss this Question