Balanced and Unbalanced
Motion
Gravity
Forces and Patterns
Grab Bag
100
What is are balanced forces?
Forces that are equal in size and opposite in direction. They do not cause a change in motion.
100
What is the name of the force that opposes motion?
A) friction
B) gravity
C) inertia
A) friction
REMEMBER - Inertia is not a force, it is a property.
100
Gravity is a _______.
A) Push
B) Pull
B) Pull
100
Which of these scenarios describes circular motion (revolution)?
A) The pendulum of a grandfather clock.
B) A cannonball flying from a cannon
C) A car moving along a straight track
D) The moon orbiting the Earth
D) The moon orbiting the Earth
100
A. Force 2 is greater than Force 1
200
Net force is the total of all forces acting on an object. When a force is balanced and the object does not move, the net force is equal to what:
A) 0
B) 10
C) 100
A) 0
200
You and your brother are trying to rearrange the furniture in your bedroom. You have moved all of the furniture except your bunkbeds. You both get on one side of the beds and push but the beds do not move. According to science, why?
A) The beds are too tall to push.
B) You need a greater force to move something that massive.
C) You and your brother are pushing the wrong direction.
B) You need a greater force to move something that massive.
200
If Earth shrinks, what will happen to it's gravity?
A) It will increase.
B) It will decrease.
C) Nothing, it will stay the same.
B) It will decrease.
REMEMBER - Gravity depends on mass and distance.
200
Force is measured in Newtons using a
A) balance
B) spring scale
C) Ruler
B) spring scale
200
A) Cell phone
300
Thomas helps his older brothers, who own a junk yard, on the weekends to earn extra money. He likes to help them push broken-down cars to the back of the junk yard because it makes him feel strong. Last Saturday, they pushed three cars with different weights, and he noticed he used different amounts of force for each one. The cars were the following weights:
white car: 2,700 kg
red car: 1,500 kg
blue car: 2,100 kg
Think about how much force is needed to move each car. Which correctly lists the cars in order from the most to least amount of force needed to move them?
A. white, blue, red
B. blue, red, white
C. red, white, blue
D. white, red, blue
A. white, blue, red
300
Mary and Ben throw tennis balls at a target. Mary’s tennis ball hits the target before Ben’s. Compare the force exerted on the tennis balls by Mary and Ben.
A) Mary exerts a greater force on the tennis ball than Ben does.
B) Ben exerts the same amount of force on the tennis ball as Mary does.
C) You cannot tell which student exerts the greater amount of force on the tennis ball.
A) Mary exerts a greater force on the tennis ball than Ben does.
300
No matter how high Juan and Susie jumped on the trampoline, they always came back down. What force caused the two children to land back on the surface of the trampoline each time they jumped in the air?
A) Bounce
B) Friction
C) Gravity
D) Spring
C) Gravity
300
As Shannon bounces a basketball, the basketball is in motion and ___________.
A) changes neither its direction nor position
B) constantly changes both its direction and position.
C) does not change its position but does change its direction.
D) never changes its position but constantly changes its direction.
B) constantly changes both its direction and position.
300
D) A ball rolling across the gym floor
400
Unbalanced forces can cause an object to change direction without changing speed. (Example - a car traveling down the road goes around a curve.)
True or False
True!
Unbalanced forces can cause any change in motion. Motion is speed and direction. Either one or both can change.
400
A) 2 seconds
B) 4 seconds
C) 6 seconds
D) 8 seconds
B) 4 seconds
A complete swing takes 4 seconds. It takes 2 seconds to swing from point A (height of 6 cm) to C (height of 0 cm). But then you must get back to point A, so that is another 4 seconds for a total of 8 seconds.
400
Earth's gravity keeps us on the Earth. Where does Earth's gravity pull towards?
A) The surface of the Earth
B) The center of the Earth
C) Earth's outer atmosphere
D) It depends on how close to the north pole you are.
B) The center of the Earth
400
All of the following are examples of objects with observable patterns of motion, EXCEPT:
A) A see-saw
B) A pendulum
C) A child swinging on a swing
D) A plant falling off a table
D) A plant falling off a table
Patterns of motion are repetitive. A plant falling off a table will not repeat.
400
C) Jupiter
500
The image shows two opposite forces acting on a rolling cart, what can we say is true about the affect of the forces on the cart?
A) It can't be determined without knowing which man is stronger.
B) It can't be determined because one man is taller than the other.
C) The forces are unbalanced and net force on the cart moves it to the left.
D) The forces are unbalanced and net force on the cart moves it to the right.
D) The forces are unbalanced and net force on the cart moves it to the right.
500
A ball is rolled down a ramp from the spot marked "start." The ball rolls down the ramp and then back up the other side, to the spot marked "finish" (represented by B). A second roll is tried. This time the ball starts at the spot marked "New start." Predict where the second ball will stop.
A) Point A
B) Point B
C) Point C
D) Point D
A) Point A
The second roll will end up at Point A. Notice on the first roll, the end point is about in line with the start point. If you start the roll higher up the side, then it will also finish at a higher spot on the other side.
500
Anything with mass has gravity, even if we can't feel most gravity except the Earth's gravitational pull. Why does the Earth's gravity seem so strong?
A) It is really massive so has a large gravitational pull.
B) It is spinning super fast so has a large gravitational pull.
C) We are stronger than all other objects except Earth's gravity.
A) It is really massive so has a large gravitational pull.
REMEMBER - Gravity is based on an objects mass and distance to other objects.
500
Jessie and Michelle are swinging at the park. Which type of motion does the swing display?
A) circular
B) periodic
C) vibrational
D) straight line
B) periodic
500
Ms. Robinson is pushing two people on swings. She is applying equal force to each person. One person weighs 80 lbs and the other weighs 135 lbs. Which person will accelerate faster from the push?.
A. the person that weighs 80 lbs
B. the person that weighs 135 lbs
C. they will accelerate the same
A. the person that weighs 80 lbs