Bài 40

What is force?

• Change the shape of an object

• Make an object move faster

• Stop or change the direction of an object

• All of the above

A force acting on an object always:

• Does not change the velocity

• Causes motion for the object

• Has a specific direction and magnitude

• Only deforms the object

When an object is at rest, we can conclude:

• No force is acting on the object

• The forces acting are balanced

• The object has no mass

• The gravitational force is zero

Which instrument is used to measure force?

• Thermometer

• Measuring tape

• Force gauge

• Clock

What is the unit of force?

• Kilogram (kg)

• Meter (m)

• Newton (N)

• Second (s)

What effects can force cause?

• Deform an object

• Make an object move

• Change the direction of an object

• All of the above

When pulling an object with a pulley, we apply:

• Gravitational force

• Frictional force

• Tension force

• Elastic force

Which of the following is a contact force?

• Gravitational force

• Magnetic force

• Pulling force by hand

• Attractive force

In which case is there no force acting?

• A marble falling from a height

• A motorcycle in motion

• A table resting on the floor

• No case

Which phenomenon is related to force?

• The sun rising

• An apple falling

• A full moon

• Water evaporating