Big Bird decided to visit three of his friends. He got in his car and drove to Elmo’s house. It took Big Bird 10 minutes to drive the 5 miles. After visiting with Elmo for 30 minutes, he headed to Bert and Ernie’s house. This drive covered 15 miles and took 20 minutes. After a 25 minute stay, Big Bird headed to Cookie Monster’s house. The Cookie Monster’s house was 10 miles away and it took Big Bird another 15 minutes to get there. Because Cookie Monster wasn’t home, he was only there for 5 minutes. Big Bird then headed home, a trip that was 20 miles away and took him 25 minutes. What was the average speed for Big Bird’s whole trip (include his visiting time)?

Average speed =

(total distance)

divided by

(total time).

That's 28.57 miles per hour.

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: