Front

During which interval is the object not moving?

Back

only at point A

Answer explanation

Velocity =0 (y axis)

Front

During which interval is the object traveling at a constant velocity? Options: B to C, D to E, F to G.

Back

It is traveling at a constant velocity during all of the intervals listed as choices.

Answer explanation

In segments B-C, D-E and F-G, veolicty is not changing.

Front

During which interval is the object speeding up? Options: A to B, B to C, D to E, E to F

Back

A to B

Answer explanation

An increase in velocity is indicated in segment A-B (only offered choice), C-D and G-H.

Front

During which interval is the object slowing down? Options: A to B, D to E, E to F, G to H

Back

E to F

Answer explanation

Segment E through F shows a decrease in velocity from 40 m/s to 20 m/s. There is no indication of other segments that show a decrease in velocity.

Front

Acceleration occurs when an object changes its speed or ______.

Back

direction

Answer explanation

Acceleration includes direction and can be positive or negative. It is a vector quantity.

Front

Which runner stopped for a rest? Options: Albert, Bob, Charlie

Back

Charlie

Answer explanation

Charlie's distance (position) did not change from 8 s to approxmimately 13 s.

Front

Which runner won the race? Options: Albert, Bob, Charlie

Back

Albert

Answer explanation

Albert finished the 100 m race in 12 s. Bob in 14 s and Charlie in 17 s. Slope=Speed= distance/time. Less time and same distance =WINNER!

Front

Choose the description of the motion of the object in segment A.

Back

Positive acceleration

Answer explanation

Segment A indicates a change of veolicty from 0 m/s to 20 m/s = postive accleraton (change in velocity (+ or -) and/or direction.

Front

Description of the motion of the object in segment C.

Back

Negative acceleration

Answer explanation

Segment C indicates a change of veolicty from 20 m/s to 0 m/s = negative accleraton (change in velocity (+ or -) and/or direction.

Front

Calculate the acceleration for segment A.

Back

2 m/s²

Answer explanation

a= V_f- V_i / t

V_f= 20 m/s

V_i= 0 m/s

t= 10 s