A car is traveling in the velocity of 20 m/s. After 30 sec it covers a distance of 1200 m. Calculate the acceleration of the car and the final velocity of the car.

Acceleration = 1.333ms-2                     Final velocity = 60ms-1

Explanation:

Final velocity is worked out with the equation s = 1/2 (u+v) t

Acceleration is worked out with the equation s =ut + 1/2at²

Initial velocity = 20ms      displacement = 1200m    time = 30s

Acceleration :   1200 = (20 x 30) + 1/2 a x 30²

                         1200 = 600 + 1 /2 x a x 900

                         1200 = 600 + 450 x a

Final velocity : 1200 = 1 /2 (20+60) x 30

                        1200 = 1/2 x 80 x 30                    

                        1200 = 40 x 30   or  1200 = 1/2 x 2400

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: