1.358 J is the kinetic energy of the car driven by Mrs. Waid.
Explanation:
Given data:
Velocity at which Mrs. Waid drives her car = 80 mph
In order to convert mph (meter per hour) into mps (meter per second),
[tex]\frac{80}{3600}=0.0222 \mathrm{m} / \mathrm{s}[/tex]
Car weighs 2500 lbs, means mass of the car, m = 2500 lbs
I kilo gram = 2.20462 pound
Therefore, 1 pound (lb)= 0.45359237 kilograms (kg).
To converting pounds into kilogram,
[tex]\frac{2500}{0.45359237}=5511.55 \mathrm{kg}[/tex]
As we know, the kinetic energy can be defined as directly proportionate to the object’s mass (m) and square of its velocity (v). The expression can be given as below,
[tex]\text { kinetic energy }(K . E)=\frac{1}{2} \times m \times v^{2}[/tex]
By substituting the given values, we get
[tex]\text { kinetic energy }(K . E)=\frac{1}{2} \times 5511.55 \times 0.0222^{2}[/tex]
[tex]\text { kinetic energy }(K . E)=\frac{1}{2} \times 5511.55 \times 0.00049[/tex]
[tex]kinetic energy (K . E)=1.358 joule[/tex]
