Two objects attract each other with a gravitational force of 25 newtons from a given distance. if the distance between the two objects is reduced by a factor of 5, what
is the changed force of attraction between them?
a.
5 newtons
b.
50 newtons
c.
125 newtons
d.
625 newtons

Astone weighing 1.5 kilograms is resting on a rock at a height of 20 meters above the ground. the stone rolls down 10 meters and comes to rest on a patch of moss. the gravitational potential energy of the stone on the moss is joules.

An insulated 40 ft^3 rigid tank contains air at 50 psia and 120°f. a valve connected to the tank is now opened, and air is allowed to escape until the pressure inside drops to 25 psia. the air temperature during this process is kept constant by an electric resistance heater placed in the tank. determine the electrical work done during this process.

Sort the images based on whether there's a force of attraction or repulsion between the magnets shown. attraction repulsion