Which statement is true because of newton's second law?
when the net force on an object decreases, the object's acceleration increases.
when the net force on an object increases, the object's acceleration decreases
when the net force on an object decreases, the object's acceleration decreases.
when the net force on an object decrea ses, the acceleration doesn't change.

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.)

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2

The friction of the water on a boat produces an acceleration of -10. m/s2. if the boat is traveling at 30. m/s and the motor is shut off, how long it take the boat to slow down to 5.0 m/s?