Question

Velocity of an object of mass 5 kg is increases from 20 m/s to 40 m/s in 2 seconds. The applied constant
force is ​

Answer 1

$\sf\small\underline\green{Given:-}$

$\sf{:\implies Mass\:of\: object\:(m)=5kg}$

$\sf{:\implies Final\: velocity\:(v)=40\:m/s}$

$\sf{:\implies Initial\: velocity\:(u)=20\:m/s}$

$\sf{:\implies Time\:taken\:by\: object=2s}$

$\sf\small\underline\green{To\:Find:-}$

$\sf{:\implies Forced\: applied\:on\: object=?}$

$\sf\small\underline\green{Solution:-}$

To solve solve this question at first we have to find out acceleration and then it's force required on the object as per the clue we have to use formula. Formula applied first equation of motion and then applying formula of force is equal to mass × acceleration.

$\sf\small\underline\green{Calculation\: begins:-}$

$\tt{\leadsto v=u+at}$

• $\sf\small\underline{v=40m/s\:\:u=20m/s\:\:t=2s}$

$\tt{\leadsto 40=20+2a}$

$\tt{\leadsto 40-20=2a}$

$\tt{\leadsto 20=2a}$

$\tt{\leadsto a=10\:m/s^2}$

• $\sf{calculate\:force\: required\:here:-}$

$\tt{\leadsto Force\:(F)=Mass\:(m)\times\: Acceleration\:(a)}$

• $\sf\small\underline{mass\:(m)=5kg\:\: Acceleration\:(a)=5\:m/s^2}$

$\tt{\leadsto Force\:(F)=5\times\:10}$

$\tt{\leadsto Force\:(F)=50\:N}$

$\sf\large{Hence,}$

$\bf{\implies Forced\: applied\:on\: object=50N}$

Answer 2

Step-by-step explanation:

Given:

• Mass of an object
• Time
• Velocity increases from 20m/sec to 40m/sec

To Find:

• The applied constant force

Solution:

Initaial velocity(u)=20m/sec

Final velocity(v)=40m/sec

Time taken= 2 sec

$\tt \leadsto \: Acceleration = \frac{v - u}{t} \\ \tt \leadsto \: \frac{40 - 20}{2} \\ \tt \leadsto \: \frac{ \cancel{20}}{ \cancel{2}} = 10$

So, acceleration=10m/sec²

Force applied = Mass × Acceleration=10×5=50N