Aloaded ore car has a mass of 950 kg and rolls on rails with negligible friction. it starts from rest and is pulled up a mine shaft by a cable connected to a winch. the shaft is inclined at 24.0° above the horizontal. the car accelerates uniformly to a speed of 2.00 m/s in 12.5 s and then continues at constant speed. (a) what power must the winch motor provide when the car is moving at constant speed? kw b) what maximum power must the motor provide? kw (c) what total energy transfers out of the motor by work by the time the car moves off the end of the track, which is of length 1,250 m?

Aperson walks first at a constant speed of 4.89 m/s along a straight line from point a to point b and then back along the line from b to a at a constant speed of 2.95 m/s. what is the average speed over the entire trip?

An electromagnet is a device in which moving electric chargers in a coil of wire create a magnet. whats one advantage of using electromagnetic in devices

69. air frictionthe velocity of the satellitea. decreases b. increases c. sometimes increases sometimedecreases d. no effect at all70. the unit of gravitational potential energy isa. jouté b. watt c. newtond. pascal71. which of the following is not influenced by a magneta. cobalt b. copper c. irond. nickel72. one joule of work done in one second by unit positive chargea.1 watt b.1 volt c.1 js d. none73. the most deviated colour of light after passing through a prisea. violet b. red c. green d. yellow4. a coin is placed below a beaker fill with water upto 12 cm isdisplaced by water isa. 9cm b.6cmс.3cmd.7cm