A typical candy bar contains 300 kilo-calories of energy. if all the energy released by eating the candy bar could be used to do work in lifting a 1000 kg car, how high could it be lifted?
1 kcal = 4184 joules
m g h = 300 * 4184
h = (300 * 4184) / (1000 * g)
To solve this problem, we can use the concept of work and energy.
The work done in lifting an object is given by the formula:
Work = Force x Distance
In this case, the force required to lift the car is equal to its weight, which is given by the formula:
Force = mass x gravity
Where:
mass = 1000 kg (mass of the car)
gravity = 9.8 m/s² (acceleration due to gravity)
Force = 1000 kg x 9.8 m/s² = 9800 N
Now, we can calculate the distance that the car can be lifted. The energy contained in the candy bar is given as 300 kilo-calories, which we need to convert to joules. 1 kilo-calorie is equal to approximately 4184 joules.
Energy = 300 kilo-calories x 4184 joules/kilo-calorie = 1,255,200 joules
Using the formula for work:
Work = Force x Distance
1,255,200 J = 9800 N x Distance
Distance = 1,255,200 J / 9800 N
Distance ≈ 128 meters
Therefore, the car could be lifted to a height of approximately 128 meters using the energy from the candy bar.