Question

A 2kg mass is moving at 3m/s. What is its kinetic energy?

Answer 1

KINETIC ENERGY

Problem:

» A 2kg mass is moving at 3m/s. What is its kinetic energy?

Answer:

• $\color{hotpink} \bold{9 \: J}$

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Formula:

To calculate the velocity of a kinetic energy, we can use formula

• $\underline{ \boxed{ \tt KE = \frac{1}{2} m{v}^{2} } }$

where,

• v is the velocity in m/s
• KE is the kinetic energy in J (joules)
• m is the mass in kg

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Based on the problem, the givens are:

• KE (Kinetic energy) = ? (unknown)
• m (mass) = 2 kg
• v (velocity) = 3 m/s

Solution:

To get the velocity, substitute the givens in the formula above then solve.

$\: \: \tt KE = \frac{1}{2} m{v}^{2} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \tt \: KE = \frac{1}{2} \times 2 \times {(3)}^{2} \\ \tt \: \: \: \: \: \: \: \: \: \: \: \: \: \: KE = \frac{1}{2} \times(2\times 9) \\ \tt KE = \underline{ \boxed{ \blue{ \tt9 \: J}}}$

Therefore, the kinetic energy is 9 Joules.