Motion and Force

The horses on this carousel are accelerating because _____.

• the speed of the horses is constantly inscreasing

• the speed of the horses is constantly decreasing

• the direction of the horses' motion is constantly changing

• the travel time is different for every ride

Instantaneous speed is the rate of motion at an instant in time. Based on this statement a reasonable conclusion is that if an object's instantaneous speed does not change over time, then _____.

• the object is quickly speeding up

• the object is very gradually slowing down

• the object is moving at a constant speed

• the object has returned to its beginning position.

Felicia wanted to pull out a particular issue from a pile of magazines. First, she tried pulling slowly, and the whole pile began to move. Then she tried pulling quickly, and the issue she wanted came out without the pile moving. The pile did not move when she pulled quickly because of the _____.

• smooth surface of the magazines

• inertia of the pile and friction

• larger force Felicia applied

• friction between the magazines

Tags

NGSS.MS-PS2-2

Which of these is measured in meters per second per second (m/s²)

• speed

• velocity

• acceleration

• displacement

A group of students is playing tug-of-war. The students on both sides of the rope are pulling with equal force. This is an example of

• unbalanced forces

• displacement

• acceleration

• balanced forces

Sometimes, people mistakenly stat that velocity and speed are the same thing. People might make such a mistake because they forget that velocity describes both speed and _____.

• volume

• force

• the time interval

• direction

Which of the following is NOT an example of unbalanced forces acting on an object?

• an acorn falling from a tree

• a car moving at a constant speed of 55 mph

• a motorcycle changing speed from 50 mph to 70 mph

• a truck slowing down as it approaches a red light

Tags

NGSS.MS-PS2-2

A sprinter runs 200 m west and 100 m east. Her displacement is _____.

• 300 m east

• 100 m west

• 300 m west

• 100 m east

speed can be calculated by dividing distance by _____.

• time

• displacement

• distance

• velocity

the speed of a motorcycle at a particular moment is its _____ speed

• negative

• continuous

• average

• instantaneous