During which interval is the object not moving?

• B to C
• C to D
• D to E
• only at point A

Answer explanation

Velocity =0 (y axis)

During which interval is the object traveling at a constant velocity?

• B to C
• D to E
• F to G
• it 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.

During which interval is the object speeding up?

• A to B
• B to C
• D to E
• E to F

Answer explanation

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

Tags

NGSS.HS-PS2-1

During which interval is the object slowing down?

• A to B
• D to E
• E to F
• G to H

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.

Tags

NGSS.HS-PS2-1

Acceleration occurs when an object changes its speed or ______.

• direction
• force
• inertia
• mass

Answer explanation

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

Tags

NGSS.HS-PS2-1

Which runner stopped for a rest?

• Albert
• Bob
• Charlie

Answer explanation

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

Which runner won the race?

• Albert
• Bob
• Charlie

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!

Tags

NGSS.MS-PS3-1

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

• Positive acceleration
• Negative acceleration
• Constant Velocity
• Not moving

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.

Tags

NGSS.HS-PS2-1

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

• Positive acceleration
• Negative acceleration
• Constant Velocity
• Not moving

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.

Calculate the acceleration for segment A.

• 2 m/s²
• 20 m/s²
• -2 m/s²
• 0 m/s²

Answer explanation

a= V_f- V_i / t

V_f= 20 m/s

V_i= 0 m/s

t= 10 s

Tags

NGSS.HS-PS2-1