9. Peter drove 57 miles down the coastline in 3 hours. What was his average speed? (6.8C)
O 171 mi/h
O 50 mi/h
O .05 mi/h
O 19 mi/h

An astronomer at the equator measures the doppler shift of sunlight at sunset. from this, she calculates that earth’s tangential velocity at the equator is 465 m/s. the centripetal acceleration at the equator is 3.41  10 2 m/s 2 . use this data to calculate earth’s radius.

What is the function of the commutator in a dc motor? a. to spin the magnet b. to change direct current into alternating current c. to change alternating current into direct current d. to spin the wire coil

Determine the amount of work done when a crane lifts a 100-n block form 2m above the ground to 6m above the ground