Question

an object of 2kg is placed at rest. how much force must be applied on it so that a velocity of 4m/s may be produced in it 4s​

Answer 1

Answer:

force equals to mass x acceleration

acceleration = (4-0)÷4s. =1m/s2

f=m×a

f=2×1

f=2kgm/s2

f=2N

Answer 2

Answer :

➥ Force applied on an object = 2 N

Given :

➤ Mass of an object (m) = 2 kg

➤ Intial velocity of an object (u) = 0 m/s

➤ Final velocity of an object (v) = 4 m/s

➤ Time taken (t) = 4 sec

To Find :

➤ Force applied on an object (F) = ?

Solution :

First we need to find acceleration of an object then we find force applied on an object from second law of Newton.

Acceleration is given by

$\tt{: \implies a = \dfrac{v - u}{t} }$

$\tt{: \implies a = \dfrac{4 - 0}{4} }$

$\tt{: \implies a = \cancel{\dfrac{4}{4}}}$

$\bf{: \implies \underline{ \: \: \underline{ \green{ \: \: a = 1 \: m/s^2}} \: \: }}$

Now ,

We find force applied on an object.

From second law of Newton

$\tt{: \implies F = ma}$

$\tt{: \implies F = 2 \times 1}$

$\bf{: \implies \underline{ \: \: \underline{ \purple{ \: \: F = 2 \: N \: \: }} \: \: }}$

Hence, the force applied on an object is 2 N.