A ball is thrown upward at an angle with a speed and direction such that it reaches a maximum height of 19.5 m above the point it was released, with no appreciable air resistance. At its maximum height it has a speed of 18.5 m/s. With what speed was the ball released?a. 26.9 m/sb. 32.3 m/sc. 37.7 m/sd. 16.2 m/se. 21.5 m/s

a. 26.9 m/s

Explanation:

Parameters given:

Height reached by ball, s = 19.5 m

Speed at maximum height (final velocity), v = 18.5 m/s

To find the initial speed of the ball, we use one of Newton's equations of motion:

where g = acceleration due to gravity

The negative sign is present because the ball is thrown upward, hence, it moves against the gravitational force.

Therefore:

The ball was released at a speed of 26.9 m/s.

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:

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.