Problem:

What is the kinetic energy of a 1500 kg car going at suburban speed of 14m/s?

Given:

• M = 1500 kg
• V = 14 m/s
• KE = ?

Formula:

• KE = ½mv²

The formula for kinetic energy is KE = 12 mv² where KE is kinetic energy, m is mass and v is the velocity. The unit for kinetic energy is the joule.

• 1 kg.m²/s² = 1 joule

Solution:

• KE = ½mv²
• KE = ½ (1500 kg) × (14 m/s)²
• KE = (750 kg) × (196 m/s)
• KE = 147, 000 j

Answer:

• The kinetic energy of car 147,000 j

________________________________

Problem:

A 95 kg anvil is about to fall from 0.9 m high bench. What is the PE?

Given:

• M = 95 kg
• G = 9.8 m/s²
• H = 0.9 m
• PE = ?

Formula:

• PE = mgh

The formula for potential energy is PE = mgh. Where PE is potential energy, m is mass, g is the gravity and his height. The unit for potential energy is the joule.

• 1 kg.m²/s² = 1 joule

Solution:

• PE = mgh
• PE = 95 kg × 9.8 m/s² × 0.9 m
• PE = 931 kg. m/s² × 0.9 m
• PE = 837.9 j

Answer:

• The potential energy is 837.9 j.

#CarryOnLearning

ANSWER:

1.) KE = 1/2 mv²

KE = 1/2 (1500kg)(14 m/s)²

KE = 750 kg (196 m²/s²)

KE = 147,000 kg m²/s²

= 147,000 N • m

* N • m = J

KE = 147,000 J

2.) PE = mgh

PE = 95 kg × 9.8 m/s² × 0.9 m

PE = 931 kg. m/s² × 0.9 m

PE = 837.9 J