-When the masses were 2 x 10^5 km apart, the gracitational force was 4 x 10^20 N. What is the force when the distance is halved and they are 1 x 10^5 km apart? -Describe a trend you notice in the (mathematical) relationship between distance and gravitational force.

An engineer designs a roller coaster so that a car travels horizontally for 152 ft, then climbs 137 ft at an angle of 34.0° above the horizontal. it then moves 137 ft at an angle of 48.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

The energy equivalent of the rest mass of an electron is

Acoil suspended freely, points in some direction when no current is passed through it . can you tell what will happen when a current is passed though it?