If an airplane with a mass of 5 tons has gravitational potential energy of 1000 kilojoules, what is its height?

The gravitational potential energy of an object, measured with respect to the ground, is given by

where m is the object's mass, g is the gravitational acceleration and h is the height of the object measured from the ground.

In our problem, the mass of the plane is m= 5 tons = 5000 kg, while the potential energy is

so we can re-arrange the previous formula and use these data to calculate h, the height of the airplane:

Julia would be observing a. static electricity was caused by her sweater rubbing against her shirt and transferring electrons. she didn't touch anything metal, so that would cancel out b.she most likely didn't rub her sweater against her hair either, so that cancels out c.she also didn't scoot across the carpet while trying to take her sweater off, that cancels out d.so that leaves a.a. is correct.