A racecar travels northward on a straight, level track at a constant speed, traveling 0.750 kilometer in 20.0 seconds. The return trip over the same track is made in 25.0 seconds. (a) What is the average velocity of the car in meters per second for the first leg of the run? m/sec (b) What is the average speed for the total trip? (Round your answer to one decimal place.) m/sec Need Help? Read It

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100 The brain mass of a human fetus during a particular trimester can be accurately estimated from the circumference of the head by m(c) = and c is the circumference (in centimeters) of the head. a. Estimate the brain mass of a fetus that has a head circumference of 20 cm. b. Find the rate of change of the brain mass for a fetus that has a head circumference of 20 cm and interpret your result. a. The brain mass of a fetus that has a head circumference of 20 cm is about (Type an integer or decimal rounded to two decimal places as needed.) C3 g. 1500 c 9 where m(c) is the mass of the brain (in grams)

Given that height of the water in a tank is increasing at a constant rate of 3.7 cm/min, use the rate of change to determine the missing values in the table. Time (in min) Height of water (in cm 2.8   3.9 23.03 5.5     43.01