Unit 6 | ES II | Acceleration

Which line (or lines) show acceleration?

• A

• B

• C

• D

• None

Answer explanation

The slope of a line on a position vs. time graph represents velocity. If a line is curved on a position vs. time graph, that means the slope is changing, which means the velocity is changing. Acceleration is the rate of change of velocity, so a curved line indicates acceleration. Acceleration means both speeding up and slowing down.

Tags

NGSS.MS-PS3-1

Which line (or lines) shows an increase in speed?

• A

• B

• C

• D

• None

Answer explanation

The slope of a line on a position vs. time graph represents velocity. The STEEPNESS of the slope in particular indicates the SPEED. Line D begins with a shallow slope that gradually gets steeper. Therefore, D shows the object speeding up.

Tags

NGSS.MS-PS3-1

Which line (or lines) shows a decrease in speed?

• A

• B

• C

• D

• None

Answer explanation

The slope of a line on a position vs. time graph represents velocity. The STEEPNESS of the slope in particular indicates the SPEED. Lines A and B begin with steep slopes that gradually become shallower. Therefore, A and B show objects that are slowing down.

Tags

NGSS.MS-PS3-1

Which line (or lines) shows an acceleration of 0 m/s²?

• A

• B

• C

• D

• None

Answer explanation

The slope of a line on a position vs. time graph represents velocity. A straight line indicates a constant velocity. Acceleration is the rate of change of velocity. Therefore, if a line is straight, there is no change in velocity, and the acceleration is 0 m/s²

Which line (or lines) show movement in the positive direction?

• A

• B

• C

• D

• None

Answer explanation

The slope of a line on a position vs. time graph represents velocity. The sign of the slope indicates direction of movement. All of these lines have a positive slope, therefore, they are all moving in the positive direction

Tags

NGSS.MS-PS3-1

Which line segment(s) show(s) acceleration?

(put a space between letters to indicate multiple line segments)

Answer explanation

The SLOPE of a line on a position vs. time graph represents VELOCITY. If a line is curved on a position vs. time graph, that means the slope is changing, which means the velocity is changing. Acceleration is the rate of change of velocity, so a curved line indicates acceleration. Acceleration means both speeding up and slowing down.

Which line segment(s) show an object at rest?

(put a space between letters to indicate multiple line segments)

Answer explanation

The SLOPE of a line on a position vs. time graph represents VELOCITY. Velocity is the rate of change in position over time. Line segment C does not change position, therefore, its velocity is 0 m/s, which means it is at rest.

Which line segment(s) shows an object moving in the negative direction?

(put a space between letters to indicate multiple line segments)

Answer explanation

Line segments B and D show a decrease in position over time, which means they have negative slopes. Slope on a position vs. time graph represents velocity. The sign of velocity represents direction, therefore, line segments B and D show movement in the negative direction.

Which line segment(s) show an increase in speed in the positive direction?

(put a space between letters to indicate multiple line segments)

Answer explanation

Line segment A shows an increase in position over time, which means its slope is positive. Slope on a Position vs. Time graph represents the velocity, therefore the velocity is positive. The sign of the velocity indicates direction. Therefore, line segment A shows motion in the positive direction.

Line segment A has a slope that gradually becomes steeper. The steepness of the slope represents speed, therefore, line segment A shows an increase in speed.

Tags

NGSS.MS-PS3-1

Which line segment(s) show a decrease in speed in the positive direction?

(put a space between letters to indicate multiple line segments)

Answer explanation

Line segment F shows an increase in position over time, which means its slope is positive. Slope on a Position vs. Time graph represents the velocity, therefore the velocity is positive. The sign of the velocity indicates direction, therefore, line segment F shows motion in the positive direction.

Line segment F has a slope that gradually becomes shallower (flatter). The steepness of the slope represents speed, therefore, line segment F shows an decrease in speed.

Tags

NGSS.MS-PS3-1