Afigure skater skates across a rink of length 50 m in 12.1 seconds. a. what is the average speed of the skater? (2 points) b. it takes the figure skater 2 seconds to increase her speed from 4 m/s to 5.3 m/s. what is the acceleration of the skater? (2 points) c. the skater is moving at a speed of 13 m/s when she starts to brake. she comes to a stop after traveling a distance of 8 m. what was her acceleration? (2 points)

(a) The skater covers a distance of S=50 m in a time of t=12.1 s, so its average speed is the ratio between the distance covered and the time taken:


(b) The initial speed of the skater is

while the final speed is

and the time taken to accelerate to this velocity is t=2 s, so the acceleration of the skater is given by


(c) The initial speed of the skater is 

while the final speed is 

since she comes to a stop. The distance covered is S=8 m, so we can use the following relationship to find the acceleration of the skater:

from which we find

where the negative sign means it is a deceleration.

Supply is the markets term for selling a specific quantity of products at various prices. the law of supply and demand is the one which affect the pricing and also the quantity the market is able to produce or make available.