Question

What would the final speed be if an object is moving at 10.8km/h and accelerated at 30m/s2 for 5 seconds? (hint: make sure your answer is in m/s)

Answer 1

Answer:

153 m/s

Explanation:

Convert initial speed to m/s and then use formula

v = u + at

Answer 2

To Find :

The Final velocity of the Object :

Given :

• Acceleration = 30 m/s²

• Initial velocity = 10.8 km/hr

• Time = 5 s

We Know :

First Equation of Motion :

$\purple{\sf{\underline{\boxed{v = u + at}}}}$

Where,

• v = Final velocity

• u = initial velocity

• t = time taken

• a = Acceleration produced

Concept :

According to the question , we have to find the final velocity in m/s , so we have to convert the initial velocity into m/s.

$\bullet\:$Initial velocity = 10.8 km/hr

We Know that , "To convert the unit from km/h to m/s , we have to multiply it by 5/18 ".

So, multiplying 10.8 km/h by 5/18 , we get :

$\implies \sf{\bigg(10.8 \times \dfrac{5}{18}\bigg) ms^{-1}} \\ \\ \\ \implies \sf{\bigg(0.6 \times 5\big) ms^{-1}} \\ \\ \\ \implies \purple{\sf{3 ms^{-1}}}$

Hence , the Initial velocity in m/s is 3 m/s.

Solution :

Given :

• Initial velocity = 3 m/s

• Acceleration = 30 m/s²

• Time = 5 s

Using , the First Equation of Motion and Substituting the values in it , we get :

$\purple{\sf{v = u + at}} \\ \\ \\ \implies \sf{v = 3 + 30 \times 5} \\ \\ \\ \implies \sf{v = 3 + 150} \\ \\ \\ \implies \sf{v = 153 m s^{-1}}$

Hence , the Final velocity is 153 m/s.