Question

An object accelerates from 10 m / s to 30 m / s in 4.0 seconds.The accelerating force is 150 N. What is the mass of the object?

Answer 1

Given :-

Initial velocity (u) =10m/s

final velocity (v) =30m/s

Time (t). =4.0 = 4 seconds

Force (f)= 150N

To find :-

We have to find the Mass of object

• First find the acceleration of object

• By first equation of motion

$\bigstar{\boxed{\textsf{\textbf{ v=u+at}}}}$

By putting values

$\longmapsto\sf v=u+at\\ \\ \longmapsto\sf 30= 10+a\times 4\\ \\ \longmapsto\sf 30-10= 4\times a\\ \\ \longmapsto\sf \cancel{\dfrac{20}{4}}= a\\ \\ \longmapsto\sf 5=a$

$\bigstar{\underline{\sf{ Acceleration \ of \ object (a)= 5m/s^2}}}$

• Now we have to find the Mass of object !

$\bigstar{\underline{\boxed{\sf{Force (f)= Mass(m)\times Acceleration (a)}}}}$

We have ,

Mass (m) = ?

Force (f)= 150N

Acceleration (a) 5m/s^2

• Find the mass of object !

$\longmapsto\sf f=ma\\ \\ \longmapsto\sf 150= m\times 5\\ \\ \longmapsto\sf \cancel{\dfrac{150}{5}}=m\\ \\ \longmapsto\sf 30=m\\ \\ \longmapsto\sf Mass = 30kg$

$\bigstar{\underline{\boxed{\textsf{\textbf{Mass \ of \ object = 30 \ kg}}}}}$

Answer 2

Given

◕ Initial velocity = 10 m/s

◕ Final velocity = 30 m/s

◕ Time = 4 seconds.

◕ Force = 150 N

To find

◕ Mass of object

Solution

Using formula :

★ a = (v - u)/t

⇒ a = (30 - 10/4

⇒ a = 20/4

⇒ a = 5 m/s²

∴ Acceleration of object = 5 m/s²

Now we know that,

★ Force = Mass × Acceleration

⇒ 150 = Mass × 5

⇒ Mass = 150/5

⇒ Mass = 30 kg

∴ Mass of object = 30 kg.