EFHS -- Rotational Motion and Gravity

If a force acts on an object without being in physical contact with it, what type of force is it?

• universal force

• contact force

• rotational force

• field force

As riders on a Ferris wheel move in a circle, how is their acceleration measured?

• how fast they move from the bottom of the ride to the top

• how fast they move from the top of the ride to the bottom

• how fast they complete a full rotation

• how fast they move through an angle known as an arc length

Why is it difficult to describe circular motion using linear quantities?

• linear motion uses trigonometric functions, like sine and cosine

• objects moving in a circle are always changing direction

• objects moving in a circle cannot be measured with meters

• circular motion is not a precise as linear motion

Two students are walking in a hallway 2 meters apart.  Calculate the gravity between them if Student 1 is 45 kg and Student 2 is 55 kg. 

• 3 x 10⁸ N

• 6.02 x 10^-23 N

• 4.1 x 10^-8 N

• 6.67 x 10^-11 N

If the string broke while the girl in the picture was spinning it around, how would the object continue moving?

• it would fall straight down

• continue in a circle briefly, then fall down

• move in a straight line, then fall down

• move towards the girl and hit her (safety goggles!)

Even though gravity is all around us, why is it considered the weakest of all the forces in nature?

• It is nearly impossible to perceive it from objects of everyday size, like tables or people.

• It cannot hold objects in place for great lengths of time.

• It cannot be measured using current technology.

• Its effects are not found outside our immediate solar system.

The gravitational force is measured in what units?

• joules, J

• newtons, N

• N·m²/kg²

• watts, W

A spinning object is said to undergo _____.

• linear acceleration

• angular energy

• linear velocity

• rotational motion