57.0- g tennis ball is traveling straight at a player at 21.0 m/ s. the player volleys the ball straight back at 25.0 m/ s. if the ball remains in contact with the racket for 0.060 0 s, what average force acts on the ball?

43.7 N

Explanation:

Given

Mass of tennis ball is =57 gm

velocity of ball=21 m/s

The player volleys the ball straight back at 25 m/s(i.e. in opposite of initial direction)

time of contact=0.06 s

We know change in momentum

initial momentum

final momentum

change in momentum

Now 2.622

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: