Question

A force of 10 N acts on a body of 2 kg for 3 seconds. Find the kinetic energy aquired by the body in 3 seconds?
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Answer 1

To Find :-

• The kinetic energy aquired by the body in 3 seconds.

Solution :-

Given,

• Force (F) = 10 N
• Initial velocity (u) = 0 ms-¹
• Mass (m) = 2 kg
• Time (t) = 3 sec

Force :- The product of mass (m) and acceleration (a).

Mathematically,

$\pink{\bold{F = ma }}$ $\bigstar$

[ Put the values ]

$\longrightarrow$ 10 = 2 × a

$\longrightarrow$ a = 10/2

$\longrightarrow$ a = 5 ms-²

Applying newton's 1st equation of motion,

$\red{\bold{v = u + at}}$ $\bigstar$

[ Put the values ]

$\longrightarrow$ v = 0 + 5 × 3

$\longrightarrow$ v = 15 ms-¹

Now, applying kinetic energy formula, we get ;

$\green{\bold{K.E = \frac{1}{2} \times mv^2}}$ $\bigstar$

[ Put the values ]

$\longrightarrow$ K.E = ¹/2 × 2 × (15)²

$\longrightarrow$ K.E = 1 × 225

$\longrightarrow$ K.E = 225 J

Therefore,

The kinetic energy aquired by the body in 3 seconds is 225 joule.