Mary weighs 450 N and she walks down a flight of stairs to a level 4.50 m below her starting point. What is the change in Mary's potential energy?
1 J
whats the PE formula? and setup?
The formula to calculate the potential energy (PE) of an object is:
PE = m * g * h
where PE is the potential energy, m is the mass of the object, g is the acceleration due to gravity (approximately 9.8 m/s² near the Earth's surface), and h is the height above a reference point.
In this case, Mary's weight of 450 N can be converted to mass using the formula:
Weight (N) = mass (kg) * gravity (m/s²)
450 N = m * 9.8 m/s²
m = 450 N / 9.8 m/s²
Once you find the mass (m), you can substitute it into the potential energy formula, along with the height (h) of 4.50 m, to calculate the potential energy change.
The formula for potential energy (PE) is given by:
PE = m * g * h
where PE is the potential energy, m is the mass of the object, g is the acceleration due to gravity, and h is the height or vertical distance.
In this case, Mary's weight is given as 450 N, which is equivalent to her mass (m) multiplied by the acceleration due to gravity (g). The acceleration due to gravity is approximately 9.8 m/s^2.
So, we can rearrange the formula as:
PE = (m * g) * h
Substituting the values given in the problem, we have:
PE = (450 N) * (4.50 m)
Calculating this expression, we get:
PE = 2025 J
Therefore, the change in Mary's potential energy is 2025 J.