Answer :
According to conservation of momentum,
(m1+m2) v = m1v1 + m2v2
Thus, velocity of the skateboard, v2= 36m/s
How to calculate the velocity of skateboard?
As per the law of conservation of momentum in an isolated system the total momentum of two or more bodies acting upon each other remains constant unless an external force is applied.
Thus,
(m1+m2) v = m1v1 + m2v2
v2= (m1+m2) v - m1v1 /m2
= (45+7) (4) -(45) (1) /7
= 253/7 = 36m/s
Hence, velocity of the skateboard, v2= 36m/s
To know the law of conservation of momentum, https://brainly.com/question/7538238
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