The mass of the quarterback is 61.2 kg.
Explanation:
mass of the football player = m1 = 102 kg
mass of the quarterback = m2 = ?
velocity of the football player = v1 = 8 m/s
According to the law of conservation of momentum:
The total momentum of a system before and after the collision remains constant. Assuming the situation as an isolated system which is not affected by any external factors, we have:
m₁v₁ + m₂v₂ = (m₁+m₂)V
Here, we need to find m₂.
We assume that the quarterback is standing still when he is attacked by the football player so v₂ = 0 m/s
After the collision both of them fall to the ground with a velocity of 5 m/s so V = 5 m/s

Keywords: momentum, velocity, law of conservation of momentum
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Answer:
v = 8.65 m/s
Explanation:
Given that,
Distance covered by the doge, d = 45 m
Time taken, t = 5.2 s
We need to find its average speed. The total distance covered divided by the total time taken is called the average speed of an object. So,

So, the average speed is 8.65 m/s.
Answer:
D. Newton's second law
Explanation:
Newton's second law of motion states that force of an object is a product of its mass and its acceleration.
Mathematically, F= ma where m is mass and a is acceleration
So from the statement above : The acceleration of an object is proportional to the force applied to it and inversely proportional to its mass , it can be seen from the formula variation as;
F= ma -----making a the subject of the formula
a= F/ m
a= 1/m * F --------- a is inversely related to m as you can see from 1/m but directly related to F hence;
Increase in mass with the same force applied causes the body to accelerate slower where as when force increases, the body accelerates faster.
If you're moving, then you have kinetic energy.
If you're not at the bottom yet, then you still have
some potential energy left.