A whale swims due east for a distance of 6.9 km, turns around and goes due west for 1.8 km, and finally turns around again and heads 3.7 km due east. (a) What is the total distance traveled by the whale? (b) What are the magnitude and direction (east or west) of the displacement of the whale? If it takes 30.0 min for the whole trip, (c)What is the average speed in km/h for the whole trip ? (d)What is the average velocity (magnitude and direction) in km/h for the whole trip?

Explanation:

a) Total distance traveled by the whale = 6.9 km + 1.8 km + 3.7 km = 12.4 km

b) the magnitude and the direction of the displacement of the whale = 6.9 km due east - 1.8 km due west = 5.1 due east

it final displacement = 5.1 km due east + 3.7 k due east = 8.8 km due east

c) average speed in km / hr = total distance traveled / total time = 12.4 km / 0.5 hr ( 30 min/ 60 min × 1 hr) = 24.8 km / hr

d) average velocity in km / h = total displacement / total time = 8.8 km / 0.5 h = 17.6 km/h

what is the speed of a softball that travels 20m in 2secs

speed = 20/2 = 10 m/s

it has to be b, about 97 percent.