g Two identical toy cars are held at rest on top of identical ramps. Car A rolls down the ramp, through a loop and then moves along a horizontal surface. Car B starts from rest at the same height, but it does NOT complete the loop. It is found that Car B has a faster speed at the finish line than Car A. What is the BEST explanation for why

The kinetic energy of Car B is greater than the kinetic energy of Car A at the finish line.

Explanation:

Both objects have the same kinetic energy at the bottom of the ramp since the ramps are identical. Since Car A passes through the loop, it losses kinetic energy before it gets to the horizontal road and thus decreasing its speed. Car B does not go through the loop so its speed as it gets to the horizontal surface is its speed at the bottom of the ramp.

As both cars move on the horizontal surface, their speed decrease further but since Car B starts with a greater speed than Car A on the horizontal surface, it will end with a greater speed than Car A at the finish line.

This is because, the kinetic energy of Car B is greater than the kinetic energy of Car A at the finish line.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation: