Gravity
A natural force. It pulls everything down towards the Earth.
Gravity
What type of simple machine is a wheelchair ramp?
an inclined plane
A bus driving on the road during the winter drives onto an icy spot and begins to slide. A decrease in which force causes the bus to slide?
Friction
A book is sitting on a table. Both the book and the table are still. We can say that the forces on these objects are
balanced
unbalanced
non-contact
electrical
Balanced
Why does a bouncing ball does not push itself into the sky and never come back?
Gravity
Which of the following best describes how a pulley system changed forces when used to lift up an object?
When the man pulls down on the rope to raise the object, the force is being transferred through the machine instead of having to lift the object by himself.
The pulley acts like a second pair of hands and lifts the object on its own.
The pulley uses force from the crate to pull the man down.
The pulley allows for energy to be transferred from the person to the crate.
When the man pulls down on the rope to raise the object, the force is being transferred through the machine instead of having to lift the object by himself.
Which of these describes an unbalanced force?
cat sleeping on a couch
pictures hung on the wall
4. girl kicks a soccer ball
girl kicking the soccer ball shows an unbalanced force
Which situation is an example of balanced forces?
A boy pushes a box uphill.
A girl speeds up on a bicycle.
A cookie jar sits on the counter.
A toy car slows down on the carpet.
A cookie jar sits on the counter.
Choose all of the phenomenon that are caused by the same force that causes objects to fall toward the surface of the Earth. (Hint) There are 2 answers.
The Earth’s orbit around the sun
Sunlight traveling to the planets
Rocks falling to the ground during a landslide
A teacher is moving classrooms across the school and wants to make the move as easy as possible. Which of the following simple machines should the teacher use for the move?
The teacher should use an inclined plane to push all of the classroom objects from one place to another.
The teacher should use a wheel and axle to move the classroom objects from one place to another.
The teacher should use a lever to lift and move the classroom objects from one place to another.
The teacher should use a pulley to pull all of the classroom objects from one place to another.
B. The teacher should use a wheel and axle to move the classroom objects from one place to another.
Students want to investigate how a marble can demonstrate a balanced force. Which situation will BEST demonstrate a balanced force?
Student 1 sets up a ramp with a book and rolls a marble down the book.
Student 2 pushes a marble along a smooth surface and the marble rolls along the surface.
Student 3 blows on a marble with a straw, but the marble does not move.
Student 4 pushes a marble across the carpet, and the marble slowly moves along the surface.
Student 3 blows on a marble with a straw, but the marble does not move.
Malik is pushing the merry-go-round.
If Malik applies a greater force to his push, what will most likely happen to the merry-go-round?
The merry-go-round will spin faster.
The merry-go-round will spin slower.
The merry-go-round will come to a stop.
The merry-go-round will change direction.
The merry-go-round will spin faster.
Why would people weigh less on the Moon than on Earth?
The Earth has more mass than the Moon.
Screws have threads that are simple machines. What kind of machine are the threads on screws?
blades
fulcrums
inclined planes
wedges
inclined planes
A fourth-grade class with 24 students is playing tug of war with a rope against their teacher. Which of the following BEST describes the expected outcome?
The 24 students and the teacher will result in a tie since their forces are balanced.
The results cannot be unpredicted since balanced and unbalanced forces are random.
The teacher will win since the forces are balanced because the teacher will have more force pulling than all 24 students.
The 24 students will win since the forces are unbalanced because they will have more force pulling on their side compared to the one teacher.
The 24 students will win since the forces are unbalanced because they will have more force pulling on their side compared to the one teacher.
There is a tug-of-war competition. The left side of the rope has 3 people while the right side of the rope has only 1 person.
Which statement provides the best description of the forces being presented?
The tug-of-war game is balanced because they are all holding onto the rope.
The tug-of-war game is unbalanced because the people on the left have more force than the man on the right.
The tug-of-war game is unbalanced because the man on the right has more force than the people on the left.
The tug-of-war game is balanced because they are all having fun.
The tug-of-war game is unbalanced because the people on the left have more force than the man on the right.
Which of the following statements best supports the claim that gravitational force (gravity) affects the motion of an object?
Gravitational force is a natural phenomenon that only affects objects in space.
Gravitational force pulls objects toward the center of the Earth, causing them to fall when dropped.
Gravitational force pushes objects away from each other, making them float in the air.
Gravitational force has no impact on objects on Earth; it only influences celestial bodies.
B. Gravitational force pulls objects toward the center of the Earth, causing them to fall when dropped.
Tommy is at the zoo with his mother, father, and little sister. His sister is twelve years old and is in a wheelchair. Tommy wants to take his sister to go see the gorilla exhibit but there are stairs. What statement best describes using a simple machine to help Tommy and his sister see the gorillas?
Tommy can carry his sister up the stairs while in her wheelchair.
Tommy can ask his mother and father to bring his sister with them as they climb the stairs.
Tommy can ask his mother or father to help push his sister’s wheelchair up the ramp.
Tommy can ask his sister to go down the slide.
Tommy can ask his mother or father to help push his sister’s wheelchair up the ramp.
Which object requires the most force to move it?
1. An open, empty cardboard box
2. A golf ball on the edge of the hole
3. A car
Car
Sonrisa has a toy car that is attached to an elastic string. Sonrisa pulls the string, applying a force to the car.
Which experiment determines what happens to the car when Sonrisa pulls on the string?
an experiment that measures how quickly the car speeds up
an experiment that measures how long the string stretches
an experiment that measures the weight of the car
an experiment that measures the thickness of the string
1. an experiment that measures how quickly the car speeds up