Acar is traveling at 26.0 m/s when the driver suddenly applies the brakes, causing the car to slow down with constant acceleration. the car comes to a stop in a distance of 120 m.
1st find acceleration -> then use it to solve.
how fast was the car moving when it was 60.0 m past the point where the brakes were applied?

a = -2.82 m/s²

v = 18.4 m/s

Explanation:

Initial velocity, u = 26.0 m/s

Final velocity, v = 0 m/s

Distance travelled, s = 120m

Using

v² = u² + 2as

0 = 26² + 2(120)a

a= -2.82 m/s²

Velocity of the car when it was 60.0m past the point where the brakes were applied:

u = 26.0 m/s

a = -2.82 m/s²

s = 60m

Using

v² = u² + 2as

v² = 26² + 2(-2.82)(60)

v² = 337.6

v = 18.4 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:

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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