Arunner runs 300 m at an average speed of 3.0 m/s. she then runs another 300m at an average
speed of 6.0 m/s.
what is her average speed for the total distance of 600m?
a 2.0 m/s
b 4.0 m/s
c 4.5 m/s
d 8.0 m/s

Asmall metal bar, whose initial temperature was 10° c, is dropped into a large container of boiling water. how long will it take the bar to reach 70° c if it is known that its temperature increases 2° during the first second? (the boiling temperature for water is 100° c. round your answer to one decimal place.) sec how long will it take the bar to reach 98° c? (round your answer to one decimal place.)

The position of a crate sliding down a ramp is given by x=(0.05t^3) m, y=(1.7t^2) m, z=(6−0.85t^5/2) m, where t is in seconds. (a) determine the magnitude of the crate's velocity when t = 2 s. (b) determine the magnitude of the crate's acceleration when t = 2 s.

What is the rate of change in a objects position?