Question

A object of mass 2kg initially at rest is moving with a acceleration of 10meter per second square .calculate is kinetic energy after covering displacement of 5metre?
by explanation ​

Answer 1

Answer:

• 100 Joules is the required Kinetic Energy .

Explanation:

Given:-

• Mass ,m = 2 kg
• Acceleration ,a = 10m/s²
• Initial velocity ,u = 0m/s
• Displacemet ,s = 5 m

To Find :-

• Kinetic Energy ,KE

Solution:-

As we have to calculate the kinetic energy of the object .

Firstly we calculate the final velocity of the object.

Using 3rd Equation of Motion

• v² = u² +2as

where,

• v is the final velocity
• a is the acceleration
• u is the initial velocity
• s is the displacemet

Substitute the value we get

→ v² = 0² + 2×10×5

→ v² = 0 + 20×5

→ v² = 100

→ v = √100

→ v = 10m/s

Now, calculating the kinetic energy .

Kinetic energy is defined as the energy possess by body due to its motion .

• KE = 1/2mv²

Where,

• KE is the Kinetic Energy
• m is the mass
• v is the speed/velocity

Substitute the value we get

→ KE = 1/2×2 × 10²

→ KE = 1/2 × 2 × 100

→ KE = 100 J

• Hence, the kinetic energy of the object is 100 Joules.

Answer 2

Given :-

A object of mass 2kg initially at rest is moving with a acceleration of 10meter per second square

To Find :-

Kinetic energy

Solution :-

We know that

$\sf v^{2} - u^{2} = 2as$

$\sf {v}^{2} - 0 = 2[10][5]$

$\sf {v}^{2} = 0 + 100$

$\sf {v}^{2} = 100$

$\sf v = \sqrt{100}$

$\sf v = 2$

Now,

$KE = 0.5 \times {10}^{2} \times 2$

KE = 100 * 1

KE = 100 J