The mass of the Book is 2.27 kg.
Explanation:
Hey there!!
Here,
Initial velocity (u) = 6m/s.
Acceleration (a) = 1.7m/s^2.
Time (t) = 4.2s.
final velocity (v) = ?
We have,

Putting their values,

7.14 = v - 6
v = 7.14 + 6
Therefore, the final velocity is 13.14 m/s.
<em><u>Hope</u></em><em><u> </u></em><em><u>it helps</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em>
Recall the definitions of
• average velocity:
v[ave] = ∆x/∆t = (x[final] - x[initial])/t
Take the initial position to be the origin, so x[initial] = 0, and we simply write x[final] = s. So
v[ave] = s/t
• average acceleration:
a[ave] = ∆v/∆t = (v[final] - v[initial])/t
Assume acceleration is constant (a[ave] = a). Let v[initial] = u and v[final] = v, so that
a = (v - u)/t
Under constant acceleration, the average velocity is also given by
v[ave] = (v[final] + v[initial])/2 = (v + u)/2
Then
v[ave] = s/t = (v + u)/2 ⇒ s = (v + u) t/2
and
a = (v - u)/t ⇒ v = u + at
so that
s = ((u + at) + u) t/2
s = (2u + at) t/2
s = ut + 1/2 at²
Answer: 4.8 s
Explanation:
We have the following data:
the mass of the raft
the force applied by Sawyer
the raft's final speed
the raft's initial speed (assuming it starts from rest)
We have to find the time 
Well, according to Newton's second law of motion we have:
(1)
Where
is the acceleration, which can be expressed as:
(2)
Substituting (2) in (1):
(3)
Where 
Isolating
from (3):
(4)
Finally: