Problem 7. At time t a particle moves so that : r(t) = ? 1/2 t 2 + 1? i + ? 1 3 t 3 − 1 ? j (a) Find the position at time t = 4. (b) Find the distance travelled from t = 0 to t = 3

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2