¿Qué energía cinética posee una pelota de tenis de 65 g que se sirve a una velocidad de 200 km / h?

Therefore, the kinetic energy of an object is proportional to the square of its velocity (speed). In other words, If there is a twofold increase in speed, the kinetic energy will increase by a factor of four. If there is a threefold increase in speed, the kinetic energy will increase by a factor of nine.

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:

0.19 m/s and 0.45 m/s