High School

To lift a 5 kg mass to a certain height, the amount of energy spent is 245 J. The mass was raised to a height of:

a) 7 m
b) 14 m
c) 21 m
d) 28 m

Answer :

Final answer:

To lift a 5 kg mass to a certain height with an energy expenditure of 245 J, the height is approximately 5 m.

Explanation:

The amount of energy spent to lift a 5 kg mass to a certain height is 245 J. To calculate the height, we can use the formula for gravitational potential energy: PE = mgh, where PE is the potential energy, m is the mass, g is the acceleration due to gravity, and h is the height.

Using the given information, we can rearrange the formula to solve for h: h = PE/(mg). Substituting the values, we have: h = 245 J/(5 kg * 9.8 m/s^2). Calculating this gives us a height of approximately 5 m.

Therefore, the correct answer is 0 m) 7 m.