T3.4 Friction and Gravitational forces

What are the two factors that affect the friction between two surfaces?

• The color of the surfaces and the temperature of the environment

• The types of surfaces involved and how hard the surfaces are pushed together

• The speed of the objects and the weight of the objects

• The size of the surfaces and the distance between them

Which type of friction is involved when a wheel rolls on a surface?

• Static friction

• Sliding friction

• Rolling friction

• Fluid friction

Rolling friction is a type of friction that occurs between which of the following?

• Two rough surfaces

• Two very smooth surfaces

• Two sticky surfaces

• Two wet surfaces

Which of the following best defines rolling friction?

• Friction that occurs when an object is stationary

• Friction that occurs when an object slides over a surface

• Friction that occurs when an object rolls across a surface

• Friction that occurs in a fluid

Static friction acts on objects when they are:

• Moving on a surface

• Resting on a surface

• Rolling on a surface

• Floating in water

Which of the following is an example of a fluid?

• Rock

• Water

• Wood

• Metal

What is the formula for calculating gravitational potential energy?

• Ep = mgh

• Ep = mg/h

• Ep = mh/g

• Ep = m/g*h

Tags

NGSS.MS-PS3-4

What is the unit of height in the formula Ep = mgh?

• Meters (m)

• Centimeters (cm)

• Inches (in)

• Feet (ft)

What is the term used when the forces on a skydiver are balanced?

• Maximum velocity

• Balanced velocity

• Terminal velocity

• Constant velocity

Tags

NGSS.MS-PS2-4

What happens to the forces on a skydiver when they reach terminal velocity?

• Forces are unbalanced

• Forces are balanced

• Only gravity acts

• Only friction acts

Tags

NGSS.MS-PS2-4