Answer :
(a) The initial velocity is, 14.8 m/s
(b) The acceleration is, 
Explanation :
By the 1st equation of motion,
...........(1)
where,
v = final velocity = 0 s
u = initial velocity
t = time = 6.35 s
a = acceleration
The equation 1 will be:

..........(2)
By the 2nd equation of motion,
...........(3)
where,
s = distance = 47 m
Now substitute equation 2 in 3, we get:

By solving the term, we get:

The acceleration is, 
Now we have to calculate the initial velocity.
Using equation 2, we gte:



The initial velocity is, 14.8 m/s
Answer:
The coefficient of kinetic friction between the block and the surface is 0.127.
Explanation:
Given that,
The mass of a block, m = 4 kg
The acceleration of the block, a = -1.25 m/s²
We need to find the coefficient of kinetic friction between the block and the surface. The force of friction is given by :

So, the coefficient of kinetic friction between the block and the surface is 0.127.
Answer: TheTroposphere contains 80% of the total gas in the atmosphere
A lever, pulley, and wheel and axel are all examples of simple machines