The answer is A.
t = ( 2h / g )^1/2 = ( 2 x 6.4 / 9.8 )^1/2 = 1.14s
Answer:
v = 27.3 m/s
Explanation:
Given that
Acceleration ,a= 4.2 m/s²
Time ,t= 6.5 s
Lets take the maximum speed gain by Thomson's= v
We know that ,if acceleration is constant then the speed v is given as
v= u + a t
v=final speed
u=initial speed
a=acceleration
t=time
Here the initial speed of Thomson's ,u = 0 m/s
Now by putting the values in the above equation we get
v= 0 + 4.2 x 6.5 m/s
v = 27.3 m/s
Therefore the maximum speed gain by Thomson will be 27.3 m/s.
According to the conservation of momentum. In this situation, the initial momentum is equal to zero.
Since,
p=mv (Momentum)
The initial velocity of the ball = 0 m/s
The initial velocity of the man = 0 m/s
Therefore,
Total Momentum = 0
Law of Conservation of momentum states that the vector sum of the final momenta must be equal to zero which means they will have the same magnitude but in opposite directions.
<span>When the ball is kicked forward along the surface with a speed 15 m/s.
</span>then the momentum will be:
p = 4 x 15 = 60 kgm/s.
Now, the momentum of the man can be calculated as:
p = 60 kgm/s
mv = 60 kgm/s
As,
mass of the man = 80kg
So,
80 × v = 60 kgm/s
v = 60÷80
v = 0.75 m/s