Determine the gain in the potential energy when a 4.0 kg rock is raised 18.000 m.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west

a skateboard rolling across the street - apex

friction

explanation:

they us to move forward and backwards