In which situation is the acceleration of the car negative? a) the velocity of a car was 75 km/h over 4 hours. b) the velocity of a car reduced from 50 km/h to 35 km/h over one minute. c) the velocity of a car increased from 40 km/h to 75 km/h over 15 minutes. eliminate d) the velocity of a car was 45 km/h at 2: 00 pm and at 4: 00 pm the velocity of the car was 85 km/h.

If a sphere and a cure have the same mass and are propelled up a ramp with the same force, which would travel father up the ramp? explain.

In the first law of thermodynamics, triangle e=q-w, what does q stand for

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?