An object with a mass of 68.5 kg is at a height of 65 m. What is its kinetic energy?

An object with a mass of 68.5 kg is at a height of 65 m. What is its kinetic energy?

• A. 4.45 kJ
• B. 4.37 kJ
• C. 34.25 kJ
• D. None of the above

Answer: (D)

To calculate the kinetic energy of an object, we use the formula for kinetic energy, which is given by: \[ KE = \frac{1}{2} mv^2 \] where \( m \) is the mass of the object and \( v \) is its velocity. The question does not provide velocity, and as a result, we cannot calculate kinetic energy directly. However, we can discuss the object's potential energy due to its height, using the formula: \[ PE = mgh \] where \( g \) (acceleration due to gravity) is approximately \( 9.81 \, m/s^2 \), and \( h \) is the height above the ground. For the object in question: - Mass \( m = 68.5 \, kg \) - Height \( h = 65 \, m \) Calculating potential energy: \[ PE = 68.5 \, kg \times 9.81 \, m/s^2 \times 65 \, m \] \[ PE \approx 68.5 \times 9.81 \times 65 \] \[ PE \approx 43794.42 \, J \text{ or } 43.

To calculate the kinetic energy of an object, we use the formula for kinetic energy, which is given by:

[ KE = \frac{1}{2} mv^2 ]

where ( m ) is the mass of the object and ( v ) is its velocity. The question does not provide velocity, and as a result, we cannot calculate kinetic energy directly.

However, we can discuss the object's potential energy due to its height, using the formula:

[ PE = mgh ]

where ( g ) (acceleration due to gravity) is approximately ( 9.81 , m/s^2 ), and ( h ) is the height above the ground.

For the object in question:

• Mass ( m = 68.5 , kg )

• Height ( h = 65 , m )

Calculating potential energy:

[ PE = 68.5 , kg \times 9.81 , m/s^2 \times 65 , m ]

[ PE \approx 68.5 \times 9.81 \times 65 ]

[ PE \approx 43794.42 , J \text{ or } 43.