Question

What is the final speed?

Answer 1

30 m/s

Step-by-step explanation:

We can first list out the 3 kinematics equations:

`v = u + at \\ {v}^(2) = {u}^(2) + 2as \\ s = ut + (1)/(2) a {t}^(2)`

Where:

v is the final velocity

u is the initial velocity

a is the acceleration

t is the time taken

s is the displacement

With all the 3 equations, we can now list the values needed for the first part of the question which is to find the acceleration for this first part.

Given:

v = 14 m/s

u = 6 m/s

t = 8s

We can use the first kinematics equation to solve for a. (v = u + at)

14 = 6 + a x 8

14 = 6 + 8a

8a = 14 - 6

8a = 8

a =

`1 \frac{m}{ {s}^(2) }`

Now with this acceleration, we can find the final speed for the second part of the question by using the same kinematics equation. (v = u + at)

Given,

u = 14 m/s

t = 16 s

a =

`1 \frac{m}{ {s}^(2) }`

v = 14 + (1)(16) = 14 + 16 = 30 m/s