Arolling ball moves from x1 = 3.4 cm to x2 = -4.2 cm during the time from t1 = 3.2 s to t2 = 6.1 s. what is its average velocity?

Answer;

= -2.62 cm/s

Solution;

Assuming a constant acceleration (0):  

v = gradient of a displacement-time graph where displacement is on the y-axis and time is on the x- axis  

v = (x2 - x1)/(t2 - t1)  

v = (-4.2 - 3.4)cm/(6.1 - 3.2)s  

v = -7.6cm/2.9s  

v = -2.62cm/s (rounded to 2 decimal places)

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