Mechanical Engineering - Engineering Mechanics - Discussion

Discussion Forum : Engineering Mechanics - Section 1 (Q.No. 50)
50.
If two bodies having masses m1 and m2 (m1>m2) have equal kinetic energies, the momentum of body having mass m1 is __________ the momentum of body having mass m2.
equal to
less than
greater than
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
33 comments Page 2 of 4.

Sairohit sandela said:   8 years ago
We know KE=P^2/2m.

For equal KE(kinetic energies).

The Square of P(momentum) is proportional to the mass.
Hence greater the mass greater is the momentum.

Melkamu said:   7 years ago
Thanks all for explaining.

Satya Jeet Verma said:   6 years ago
K.E= p^2/2*m.
KE1=KE2.
P1^2/2*m1=P2^/2*m2.
since m1>m2.
So P1>P2.

Vishnu said:   5 years ago
V1 can't be equal to v2 as if they were equal how come kinetic energy be equal as mass are different? Explain please.

Kamran Ashraf said:   5 years ago
Ke1 = ke2,
m1v1^2 = m2v2^2,
m1v1 * v1 = m2v2 * v2,
Moment1 *v1 = Moment2 *v2,
Moment1/Moment2 = v2/v1.

m1>m2 so for equal KE v2>v1 i.e v2/v1 >1;
Moment1>Moment2.

Mohsin Ali said:   3 years ago
You are absolutely right @Johny.

Ajay Dubile said:   2 years ago
Good, thanks all.

Gaurav said:   3 weeks ago
Thanks all.

Pawan kumar said:   9 years ago
(1/2)m1v1^2 = (1/2)m2v2^2 (equation showing the equal kinetic energy where m1>m2).

By cancelling (1/2) on both sides, we get,

m1v1^2 = m2v2^2.
p1v1 = p2v2 = constant (denoting p = mv which is momentum).

So, to make the product of two quantities equal, p1>p2.

Pawan kumar said:   9 years ago
K.E1= K.E2.
(1/2)m1v1^2 = (1/2)m2v2^2.
(equation showing the equal kinetic energy where m1>m2).

By cancelling (1/2) on both sides, we get,

m1v1^2 = m2v2^2.
p1v1 = p2v2 = constant (denoting p = mv which is momentum).

p1/p2= v2/v1.
You have to know that ratio of v2/v1 should be greater than 1.
So,
m1v1/m2v2=some value greater than 1.
m1v1=some value greater than 1 x m2v2.
So m1v1 will be greater than m2v2 by the value of the ratio of v2/v1.


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