~*Noor*~
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Momentum...Please urgent help!
My Question:
A 1500 kg car moving east at 38 m/s collides with a 1780 kg car moving south at 15 m/s and the two cars stick together.
(a) What is the velocity of the cars right after the collision? _______m/s ______o
(b) How much kinetic energy was converted to another form during the collision? ______kJ
My attempt:
So i used the momentum formula and got the total momentum before collision and made it equal to the momentum after the collsion but didn't get the right answer.
Before collision: car1:
p=m1v1=(1500kg)(38m/s)=57000
car2:
p=m2v2=(1780kg)(-15m/s)=-26700
p1+p2=P total
57000+(-26700)=30300
After collision: car1:
p=1500v1
car2:
p=1780v2
v1=v2 because of collision therefore
30300=(1500+1780)v
v=9.24m/s
when i took out the negative i got a different answer (25.5m/s) which was also wrong.
Part B I've no idea how to do
Please tell me what I'm doing wrong!
My Question:
A 1500 kg car moving east at 38 m/s collides with a 1780 kg car moving south at 15 m/s and the two cars stick together.
(a) What is the velocity of the cars right after the collision? _______m/s ______o
(b) How much kinetic energy was converted to another form during the collision? ______kJ
My attempt:
So i used the momentum formula and got the total momentum before collision and made it equal to the momentum after the collsion but didn't get the right answer.
Before collision: car1:
p=m1v1=(1500kg)(38m/s)=57000
car2:
p=m2v2=(1780kg)(-15m/s)=-26700
p1+p2=P total
57000+(-26700)=30300
After collision: car1:
p=1500v1
car2:
p=1780v2
v1=v2 because of collision therefore
30300=(1500+1780)v
v=9.24m/s
when i took out the negative i got a different answer (25.5m/s) which was also wrong.
Part B I've no idea how to do

Please tell me what I'm doing wrong!