Awater balloon dropped from a window high above the ground falls y = 4.9t2 m in t sec. find the balloon’s (a) average speed during the first 3 sec of fall. (b) speed at the instant t = 3.

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies.

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative

Two students, each riding bicycles, start from the same apartment building and ride to the same building on campus, but each takes a different route. the first student rides 1100 m due east and then turns due north and travels another 1430 m before arriving at the destination. the second student heads due north for 1930 m and then turns and heads directly toward the destination.at the turning point, how far is the second student from the destination?