Car a travels from new york to miami at 25 m/s. car b travels from new york to chicago, also at 25 m/s. car a and car b have speeds and velocities.
a) equal, equal

b) equal, different

c) different, equal

d) different, different

B) equal, different

Explanation:

- Speed is the ratio between the distance covered by an object and the time taken:

And it is a scalar, because it has only a magnitude, so it does not depend on the direction of the motion.

- Velocity is instead a vector, consisting of a magnitude (which is equal to the ratio between the displacement and the time taken:

and a direction.

In this problem, the two cars have same speed (25 m/s) but different velocities, because they travel in different directions.

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:

the total distance traveled by the car is

30km + 49km = 79 km .