Introduction to forces
What is the unit of force?
Newton
What happens to a tennis ball when it hits the ground?
It deforms
What is friction?
a) A force that acts between two surfaces in contact
b) A force that pulls objects downward
c) A force that pushes objects upward
a) A force that acts between two surfaces in contact
Which of the following is a force that acts at a distance?
a) Friction
b) Gravity
c) Push
Gravity
What are balanced forces?
a) Forces that act in the same direction and add up
b) Forces that are equal in size and opposite in direction
c) Forces that make objects move faster
Forces that are equal in size and opposite in direction
Which of the following is a non- contact force?
a) Friction
b) Air resistance
c) Gravity
Gravity
What is the name of the force that pulls a stretched bungee cord back to its original length?
Tension
Which of the following is an example of a drag force?
a) Friction between shoes and the ground
b) Air resistance acting on a parachute
c) Gravity pulling an object down
b) Air resistance acting on a parachute
What is the difference between weight and mass?
a) Weight is the amount of matter in an object; mass is the force acting on it
b) Weight is a force; mass is the amount of matter in an object
c) Weight and mass are the same
Weight is a force; mass is the amount of matter in an object
What happens to an object when forces acting on it are balanced?
a) It speeds up
b) It slows down
c) It stays at rest or moves at a constant speed
It stays at rest or moves at a constant speed
What does a force do?
a) Only change the shape of an object
b) Makes object move, stop, or change direction.
c) Only makes object move faster.
Makes object move, stop, or change direction
What is mean by elastic limit of the spring?
a) The maximum force a spring can withstand before breaking.
b) The point beyond which a spring will not return to its original length
c) The amount of force needed to start stretching a spring
The point beyond which a spring will not return to its original length
Why is friction useful when walking?
a) It makes surfaces slippery
b) It provides grip between your shoes and the ground
c) It reduces your weight
b) It provides grip between your shoes and the ground
What is the unit of weight?
a) Kilogram (kg)
b) Newton (N)
c) Gram (g)
Newton
What are unbalanced forces?
a) Forces that cancel each other out
b) Forces that are equal and opposite
c) Forces that do not cancel out and cause a change in motion
Forces that do not cancel out and cause a change in motion
Which statement is true about contact force?
a) They act without touching the object
b) They require physical contact between objects
c) They are weaker than non- contact forces
They require physical contact between objects
What does Hook's law state?
The extension of a spring is proportional to the force applied.
What happens to friction when surfaces are lubricated?
b) Friction decreases
Name two examples of forces that act at a distance.
Gravity, Magnetic force, Electrostatic force
How do unbalanced forces affect the speed of an object?
a) They keep the speed constant
b) They make the object move in a circle
c) They cause the object to speed up or slow down
They cause the object to speed up or slow down
A student pushes a block with a force 5N, but the block does not move. What is the most likely reason?
a) The block is too heavy
b) There is no gravity acting on the block
c) Friction is balancing the applied force
The friction is balancing the applied force.
If a string obeys Hook's law, what will its graph of force and extension look like?
a) A curve that flattens out
b) A straight line through the origin
c) A horizontal line
a straight line through the origin
What is meant by the term “streamlined” in reducing drag forces?
a) Making an object heavier
b) Giving an object a shape that allows air or water to flow smoothly around it.
b) Giving an object a shape that allows air or water to flow smoothly around it
What would happen to your weight in space?
a) It would increase
b) It would decrease
c) It would stay the same
It would decrease
When a car brakes, which force is bigger: the driving force or the braking force?
a) Driving force
b) Braking force
c) Both are equal
Braking force
What are the interaction pairs when a book rest on a table?
The book pushes the table down, and the table pushes the book up.
What happens when you stretch a spring beyond its elastic limit?
It becomes permanently deformed
Name two drag forces acting on an airplane in flight.
Air resistance and water resistance
If an object has a mass of 10 kg and the gravitational field strength is 10 N/kg, what is its weight?
100N
If two teams in a tug-of-war pull with equal force in opposite directions, what is the result?
a) The rope moves toward the stronger team
b) The rope stays still because forces are balanced
c) The rope moves in circles
The rope stays still because forces are balanced