Question

a body of mass 8 kg initially at rest is subjected to a force of 64 newton what is the kinetic energy acquired by the body at the end of 10 seconds
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Answer 1

Required Answer:-

We have:

• Mass of the body = 8 kg
• Force applied = 64 N
• Initially at rest (u = 0)
• Time taken = 10 s

To FinD:

• Kinetic energy acquired by the body at the end of 10 seconds$?$

Step-by-Step Explanation:

We have the force applied and the mass of the body. By using Newton's 2nd law, Finding the acceleration:

⇒ F = ma

⇒ a = F / m

⇒ a = 64 kg m/s² / 8 kg

⇒ a = 8 m/s²

Now we have the accleration, initial velocity and time taken is already given in the question.

Finding the final velocity by 1st equation of motion because we need it to find the kinetic energy of the body.

⇒ v = u + at

⇒ v = 8 m/s² × 10s

⇒ v = 80 m/s

Now finding the kinetic energy of the body:

⇒ K.E. = 1/2 mv²

⇒ K.E. = 1/2 × 8 × (80)² J

⇒ K.E. = 25600 J

Hence:

• The kinetic energy acquired by the body at the end of 10 seconds is 25600 Joules.

Answer 2

Answer :-

✮ 25600 J ✮

Given:-

• Mass of body (M) = 8 kg
• Force applied (F) = 64 N
• Initial velocity (U) = 0
• Time taken (T) = 10 sec

To find :-

Kinetic energy

SoluTion :-

Firstly let's find Acceleration

$\huge \boxed { \bf \: F\: = ma }$

Here,

F = Force

M = Mass

A = Acceleration

➸ 64 = 8/a

➸ 64 / 8 = a

➸ 8 = a

➥ Acceleration of body = 8 m/s

Now,

We will find final velocity

$\huge \boxed { \bf \: V \: = U +AT}$

Here,

V = Final Velocity

U = Initial velocity

A = Acceleration

T = Time taken

➸ V = 0 + 8 × 10

➸ V = 8 × 10

➸ V = 80 m/s

Now,

Finding kinetic energy

$\huge \boxed { \bf \: KE = \frac{1}{2} \times MV {}^{2} }$

Here,

KE = Kinetic energy

M = Mass

V = Final Velocity

➸ KE = ½ × 8 × 80²

➸ KE = ½ × 8 × 80 × 80

➸ KE = 1 × 4 × 80 × 80

➢ Kinetic energy = 25600 Joule