General Knowledge - Physics - Discussion

Give me the reason for momentum.

1)According to newton,s 2nd law force = rate of change of momentum i.e.,momentum=m*v

F= M*(D*V/DT)=M*A

so it is case of m1v1 and m2v2

m1 is not = m2

hence v1 is not = v2

now Newton's 3rd law come in pictutre during impact

F1=F2 ......(equal and opposite reaction)

hence m1a1=m2a2

momentum1=momentum2

2)

it can be a case of special relativity

increase in velocity= increase in inertia = increase in enrgy

then apply law of conservation of energy again newtons 3rd law

3)

concider it is case of closed system between two bodies

u get the answer

momentum = force* time

Force=rate of change of momentum.

As force & time both are constant. So we get momentum=constant.

If the ans is not velocity then definitly not option B.

Because P=mv. if v changes then how can p same in both cases.

Assume case 1;
m=1kg v=1m\s then p=1kgm\s

Assume case 2;
m=2kg v=2m\s then p=4kgm\s.

All options are not satisfactory.

Second law of motion by newton will greatly explained it.

In this case momentum=m*v

Here v is 0 so if mass m1 is 3 and m2 is 4 but v is 0.

So momentum remains constant.

We know that momentum = mass*velocity.

Even if we suppose that both acquire same velocity,

Then also the answer is not true as both have different masses.

Also among the given options, velocity is the only quantity which does not depend on mass and else other quantities do depend on mass.

k.e. = 1/2*mass*velocity square.

p = m*v.

Acceleration = force/mass.

So as a conclusion velocity should remain constant.

Here the velocity, acceleration and momentum all will be same for both the objects. How it could be only momentum?

F= ma.
Therefore a=F/m.

F is same in both cases but m is different therefore they can not have same acc.

Suppose,

Min first case be 2 and second case b 4. And force is 10 then in first case acc = 5 whereas in second case it is = 5/2. Which is not equal.

Now ke = 1/2 mv(square).
V = under root of ( 2 ke /m ).

Case 1 : m is 2 and ke is 10.
V =underfoot of (2*10/2)= underfoot 10.

Case 2 : M = 4 ke = 10

V = underfoot of (2*10/4) = under root of 5. Which is again not equal.
Then. V = ut + (1/2) at square in this case acc is changing again as v proved above therefore. It's not correct option.

And

Momentum.

P = f*t therefore both r constancent in ques. Therefore momentum is the answer.