Using the law of conservation of momentum
m1u1+m2u2=m1v1+m2v2
Where m1 is mass of first object
m2 is mass of second object
u1 and u2 are initial velocities of object 1 and 2 respectively
v1 and v2 are final velocities of object 1 and 2 respectively
Here, they are moving as a system after collision. Thus they will posses same final velocity
m1u1 +m2u2=v(m1+m2)
Substituting values
600*4+0=v(600+400)
2400=v*1000
v=2.4 m/s
Now momentum of system
p=Mv
p=(600+400)*2.4
p=1000*2.4
Therefore p=2400 kg m/s
Hope this helps :)
Kinetic energy because of the wood plank is just still and not moving it’s potential but since it’s asking which one it doesn’t have it doesn’t have kinetic energy cause it’s not moving
The rocket engine works on the basic principle proposed by Newton which is Newton’s Third Law.
Answer:
D,B,C,A,C
Explanation:
I believe that is the correct answers but it is unclear. I don't think the key for the second last question would let the current flowing so the bulb would be off.
