Question

A car park has three floors. the ground floor is at street level. the first floor is 4.0m above the ground floor, the second floor is 3.0m above the first floor. how much energy does it take to lift an 800kg hatchback to the top level from the street?

Answer 1

To lift an 800kg hatchback to the top level of a car park, 4.0m above the ground floor and 3.0m above the first floor, we use the gravitational potential energy formula PE = mgh which calculates to 54.816 kJ of energy.

Step-by-step explanation:

To calculate the energy required to lift an 800kg hatchback to the top level of a car park from street level, we will use the concept of gravitational potential energy (PE). This is calculated with the formula PE = mgh, where m is mass, g is the acceleration due to gravity (9.81 m/s²), and h is the height to which the object is lifted. In this case, the total height h is the sum of the height from the ground floor to the first floor (4.0 m) and the height from the first floor to the second floor (3.0 m), which totals 7.0 m. Thus, the potential energy is:

PE = 800 kg × 9.81 m/s² × 7.0 m.

Upon solving this, we get:

PE = 800 × 9.81 × 7
PE = 54816 Joules or 54.816 kJ

This is the energy needed to lift the hatchback to the top level.