Acar's engine is only 12 % efficient at converting chemical energy in gasoline to mechanical energy. if it takes 18000 n of force to keep the car moving at a constant speed of 21 m/s, how much chemical energy would be needed to move the car a distance of 450m at this speed?

State the right hand rule of the direction of magnetic field in a conductor carrying current

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 790 n/m. it is initially at rest on an inclined plane that is at an angle of 28 degrees with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is k = 0.14. in the initial position, where the spring is compressed by a distance of a = 0.18 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

Who was the first scientist to measure speed as distance over time?