Answer:

Potential and Kinetic Energy Calculations:

1. A 10 kg mass is lifted to a height of 2 meters. What is its potential energy at its position?

Formula:

PE=mgh

m=mass of object

g= acceleration due to gravity (9.8 m/s^{2}s

2

)

h=height of the object (in meters)

Given:

m= 10 kg ; g= 9.8 m/s^{2}s

2

; h= 2m

Solution:

PE=mgh

= 10 kg x 9.8 m/s^{2}s

2

x 2m

= 196 kg·m/s^{2}s

2

·m

= 196 N·m

= 196 J ⇒ is the Potential Energy of the 10kg mass lifted at 2m

2. Calculate the Kinetic energy of a truck that has a mass of 2900 kg and is moving at 55 m/s.

Formula:

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

2

1

mv

2

m=mass of object

v=velocity of the object

Given:

m= 2900 kg ; v= 55 m/s

Solution:

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

2

1

mv

2

= \frac{1}{2} (2900kg)(55m/s)^{2}

2

1

(2900kg)(55m/s)

2

= 4,386,250 kg·m^{2}m

2

/s^{2}s

2

= 4,386,250 J

= 4,386.250 KJ ⇒ is the Kinetic Energy of the truck

3. What is the kinetic energy of a 3kg ball that is rolling 2 m/s?

Formula:

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

2

1

mv

2

m=mass of object

v=velocity of the object

Given:

m= 3 kg ; v= 2 m/s

Solution:

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

2

1

mv

2

= \frac{1}{2} (3 kg)(2m/s)^{2}

2

1

(3kg)(2m/s)

2

= 6 kg·m^{2}m

2

/s^{2}s

2

= 6 J ⇒ is the Kinetic Energy of the ball