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## 3. Thekinetic energy of an object of mass, m moving with a velocity of 5 ms-t is 25 J. What will be its Toinetic energy when

Question

3. Thekinetic energy of an object of

mass, m moving with a velocity

of 5 ms-t is 25 J. What will be its

Toinetic energy when its velocity

is doubled? What will be its

Icinetic energy ruhen its velocity

is increased three times?

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Physics
6 months
2021-07-13T17:36:22+00:00
2021-07-13T17:36:22+00:00 1 Answers
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## Answers ( )

Answer:

1. 100 J

2. 225 J

Explanation:

We’ll begin by calculating the mass of the object. This can be obtained as follow:

Velocity (v) = 5 ms¯¹

Kinetic energy (KE) = 25 J

Mass (m) =?

KE = ½mv²

25 = ½ × m × 5²

25 = ½ × m × 25

25 = 25m / 2

Cross multiply

25m = 25 × 2

25m = 50

Divide both side by 25

m = 50 / 25

m = 2 Kg

1. Determination of the kinetic energy when the velocity is doubled.

Mass (m) = 2 Kg

Velocity (v) = double the initial velocity

= 2 × 5 ms¯¹

= 10 ms¯¹

Kinetic energy (KE) =?

KE = ½mv²

KE = ½ × 2 × 10²

KE = ½ × 2 × 100

KE = 100 J

2. Determination of the kinetic energy when the velocity increased three times.

Mass (m) = 2 Kg

Velocity (v) = three times the initial velocity

= 3 × 5 ms¯¹

= 15 ms¯¹

Kinetic energy (KE) =?

KE = ½mv²

KE = ½ × 2 × 15²

KE = ½ × 2 × 225

KE = 225 J