A 3 kg trolley is travelling at 3 ms-1 an object of mass 1 .5kg is dropped onto it what is the new velocity of the object
My question is asking for the formulas that are need and the answer of how to work out this question

Use conservation of momentum:

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Originally Posted by ebaines

Use conservation of momentum:

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so could u help me out into working this question please because i don't quite understand

Momentum is determined by an object's mass multiplied by its velocity. In many physics problems we can apply the concept of conservation of momentum, which says that the momentum of a system remains constant. So in this case the momentum of mass number 1 (the 3 Kg trolley) travelling at velocity v_1 (3 m/s) should equal the momentum of mass 1 plus mass 2 (the 1.5 Kg extra mass) traveling at some unknown new velocity, v_2. You should be able to solve for v_2. Post back with your attempt and we'll check it for you.

OK so for m1v1=(m1+m2)v2
I did m1(3) v1(3)=m1(3)+(1.5)=4.5
is it correct

Quote:

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Originally Posted by ebaines

Momentum is determined by an object's mass multiplied by its velocity. In many physics problems we can apply the concept of conservation of momentum, which says that the momentum of a system remains constant. So in this case the momentum of mass number 1 (the 3 Kg trolley) travelling at velocity v_1 (3 m/s) should equal the momentum of mass 1 plus mass 2 (the 1.5 Kg extra mass) traveling at some unknown new velocity, v_2. You should be able to solve for v_2. Post back with your attempt and we'll check it fo you.

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OK so for m1v1=(m1+m2)v2
I did m1(3) v1(3)=m1(3)+(1.5)=4.5
is it correct

So far so good - you have values for m1, v1, and (m1+m2). Now, what do you get for v2?

Helooooooooooooo... anybody

For v2 I got 4.5