During an automobile crash test, the average force exerted by a solid wall on a 1,700 kg car that hits the wall is measured to be 170,000 N over a 0.14 s time interval. What was the initial speed of the car (in m/s) prior to the collision, assuming the car is at rest at the end of the time interval

14 m/s

Explanation:

Step One:

Given data:

mass of automobile m= 1700kg

Force F= 170,000 N

time t= 0.14s

v= ??

Required

The velocity of the car

Step two:

From the expression given below, we can find the velocity

Ft= mv

make v subject of the formula

v= Ft/m

v= 170000*0.14/1700

v=23800/1700

v=14 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:

option number c is the right answer.