Influenced by the gravitational pull of a distant star, the velocity of an asteroid changes from from +19.9 km/s to −18.3 km/s over a period of 1.97 years.
(a) what is the total change in the asteroid's velocity? (indicate the direction with the sign of your answer.) m/s
(b) what is the asteroid's average acceleration during this interval? (indicate the direction with the sign of your answer.)

Given:

Initial velocity of the asteroid, v = 19.9 km/s = 19900 m/s

(since, 1km = 1000 m)

Final velocity of the asteroid, v' = - 18.3 km/s = -18300 m/s

time period, T = 1.97 years

Solution:

(a). Total change in velocity, :

= v' - v

= - 18300 - 19900 = - 38200 m

here, negative sign is indicative of the fact that the motion of the asteroid is in the downward direction.

(b) Asteroid's average acceleration, a:

a =

a =

a =

Here, the negative sign is the indication of deceleration of the asteroid in the downward direction.

a lot of it means it can be "burned" for energy and sold at one price. if it is scarce, the price will go up