Warm Ups 2.27.12
2.27.12
Using your computer find a good definition of a force, balanced force, and unbalanced force. Include a picture or diagram of each.
Force: energy that cause an object to change in speed, change in direction, or a change in shape. Push or pull. Energy applied to an object, may or may not move.
Balanced force: when the forces pushing (or pulling) an object in one direction are the same size as the forces acting in the opposite direction. Balanced objects have a net force of 0.
Unbalanced forces:
When 2 forces are not equal they work against each other. One is stronger that the other, will move one direction or another, change in motion. Causes acceleration.
2.28.12
Explain how tug of war demonstrates an unbalanced force.
One side will have more strength and they will overpower the other side.
2.29.12
What is the net force acting on the object?
The net force is 10 N.
Which direction will the table move?
The table will go left.
Is this a balanced or unbalanced force? How do you know?
This is an unbalanced force, because it is changing direction and it has a net force greater than 0.
Explain how tug of war demonstrates an unbalanced force.
One side will have more strength and they will overpower the other side.
2.29.12
What is the net force acting on the object?
The net force is 10 N.
Which direction will the table move?
The table will go left.
Is this a balanced or unbalanced force? How do you know?
This is an unbalanced force, because it is changing direction and it has a net force greater than 0.
3.1.12
What is the net force acting on the object?
The net force is100 N.
Is the force balanced or unbalanced?
It is unbalanced, because if it was balanced, it would have a net force of 0.
Describe how the forces will affect the motion of the object.
Both forces are moving the object to the right with 100 N of force.
3.2.12
What is the net force acting on the object?
The net force is 0 Newton's.
Are the forces balanced or unbalanced?
The forces are balanced.
Describe how the motion will affect the object.
The object will stay in place as it is balanced and it is not accelarating.
What is the net force acting on the object?
The net force is 20 Newtons.
Are the forces balanced or unbalanced?
The forces are unbalanced.
Describe how the motion will affect the object.
The object will go to the right as there is more force on that side.
3.5.12
The student is expected to differentiate between speed, velocity, and acceleration.
Which would have the most displacement- a cheetah running across the plain to catch his prey, or a Monarch butterfly migrating from Canada to Mexico?
Displacement: moving from one place to another, point A to point B. The butterfly has more displacement, as there is a greater distance.
3.7.12
How would you graph constant speed?
The x-axis would be labeled Time (seconds) and the y-axis would be labeled Distance (meters).
How would you graph acceleration?
The x-axis would be labeled Time (seconds) and the y-axis would be labeled Speed.
3.9.12
What is the average velocity of the car between 2 and 5 seconds?
The average velocity is about 14 m/s.
If the Y-axis was labeled velocity (m/s) what would be the average acceleration between 2 seconds and 4 seconds?
The acceleration would be about 12 m/s2.
If the graph represented speed and not velocity what would it look like and why?
The line would have to go back to the beginning point. (A to A NOT A to B).
3.19.12
1. Between which two points does the object stop?
The object stops between C and D.
2. Between which two points does the object have the greatest speed?
It has the greatest speed from Point A to Point B.
3. Describe and compare the motion of the object between Points A and B to Points B and C.
From Points A to B the line goes up, which shows the person is moving away from the object. While from Point B to C the person is moving closer to the object.
4. At which two points does the object change directions?
It changes directions from Point B to D.
5. Calculate the speed at Point E.
The speed at Point E is 15/8 M/S.
6. What is the average speed of the runner? What is the average velocity of the runner?
The average speed is 9 m/s. (distance over time) Velocity: 50/10. (displacement over time)
3.20.12
What is the acceleration between 3 and 5 seconds?
2 m/s2. (Final Velocity – Initial Velocity
Change in Time) = Acceleration.
3.21.12
What is the acceleration between 2 and 4 seconds?
2 m/s2.
What would the velocity be at 7 seconds?
14 m/s.
3.22.12
If you were to jump off a tall bridge and then jump out of a moving airplane, would you have the same falling sensation or would the sensation feel different? Why?
The falling sensation would feel different as the bridge is still and the airplane is moving.
3.26.12
Using your weekend experiences, give an example of Newton's first law of motion.
When I threw the tennis ball for my dogs, it would continue moving until acted upon by and outside force, such a s friction or my dogs catching it.
3.29.12
A 4.0 kg object is moving across a friction-free surface with a constant velocity of 2 m/s. Which of the following horizontal forces is necessary to maintain this state of motion.
A. 0 N
B. 0.5 N
C. 2.0 N
D. 8.0 N
E. depends on the speed.
The answer is A, 0 Newtons.
4.2.12
What is the force the man is applying on the car?(F=M*A)
He is applying 50 N.
What is the acceleration of the sled? (A=F/M)
The acceleration is 2 m/s2.
4.3.12
Two forces of 6 N and 3 N act upon an object in opposite directions. What would be the acceleration of this object if it has a mass of 100 kg?
A) 0.03 m/s2
B) 0.09 m/s2
C) 0.3 m/s2
D) 0.9 m/s2
The answer is A 0.03 m/s2.
4.4.12
Think of it! Identify as many pairs of action-reaction force pairs in the diagram.
The truck/tractor is driving forward, and the person is straining to hold on to the rope. The is resisting being pulled and his feet are going forward while the elephant goes backwards. The tires go forward and the rope is resisting.
What is the net force acting on the object?
The net force is100 N.
Is the force balanced or unbalanced?
It is unbalanced, because if it was balanced, it would have a net force of 0.
Describe how the forces will affect the motion of the object.
Both forces are moving the object to the right with 100 N of force.
3.2.12
What is the net force acting on the object?
The net force is 0 Newton's.
Are the forces balanced or unbalanced?
The forces are balanced.
Describe how the motion will affect the object.
The object will stay in place as it is balanced and it is not accelarating.
What is the net force acting on the object?
The net force is 20 Newtons.
Are the forces balanced or unbalanced?
The forces are unbalanced.
Describe how the motion will affect the object.
The object will go to the right as there is more force on that side.
3.5.12
The student is expected to differentiate between speed, velocity, and acceleration.
Which would have the most displacement- a cheetah running across the plain to catch his prey, or a Monarch butterfly migrating from Canada to Mexico?
Displacement: moving from one place to another, point A to point B. The butterfly has more displacement, as there is a greater distance.
3.7.12
How would you graph constant speed?
The x-axis would be labeled Time (seconds) and the y-axis would be labeled Distance (meters).
How would you graph acceleration?
The x-axis would be labeled Time (seconds) and the y-axis would be labeled Speed.
3.9.12
What is the average velocity of the car between 2 and 5 seconds?
The average velocity is about 14 m/s.
If the Y-axis was labeled velocity (m/s) what would be the average acceleration between 2 seconds and 4 seconds?
The acceleration would be about 12 m/s2.
If the graph represented speed and not velocity what would it look like and why?
The line would have to go back to the beginning point. (A to A NOT A to B).
3.19.12
1. Between which two points does the object stop?
The object stops between C and D.
2. Between which two points does the object have the greatest speed?
It has the greatest speed from Point A to Point B.
3. Describe and compare the motion of the object between Points A and B to Points B and C.
From Points A to B the line goes up, which shows the person is moving away from the object. While from Point B to C the person is moving closer to the object.
4. At which two points does the object change directions?
It changes directions from Point B to D.
5. Calculate the speed at Point E.
The speed at Point E is 15/8 M/S.
6. What is the average speed of the runner? What is the average velocity of the runner?
The average speed is 9 m/s. (distance over time) Velocity: 50/10. (displacement over time)
3.20.12
What is the acceleration between 3 and 5 seconds?
2 m/s2. (Final Velocity – Initial Velocity
Change in Time) = Acceleration.
3.21.12
What is the acceleration between 2 and 4 seconds?
2 m/s2.
What would the velocity be at 7 seconds?
14 m/s.
3.22.12
If you were to jump off a tall bridge and then jump out of a moving airplane, would you have the same falling sensation or would the sensation feel different? Why?
The falling sensation would feel different as the bridge is still and the airplane is moving.
3.26.12
Using your weekend experiences, give an example of Newton's first law of motion.
When I threw the tennis ball for my dogs, it would continue moving until acted upon by and outside force, such a s friction or my dogs catching it.
3.29.12
A 4.0 kg object is moving across a friction-free surface with a constant velocity of 2 m/s. Which of the following horizontal forces is necessary to maintain this state of motion.
A. 0 N
B. 0.5 N
C. 2.0 N
D. 8.0 N
E. depends on the speed.
The answer is A, 0 Newtons.
4.2.12
What is the force the man is applying on the car?(F=M*A)
He is applying 50 N.
What is the acceleration of the sled? (A=F/M)
The acceleration is 2 m/s2.
4.3.12
Two forces of 6 N and 3 N act upon an object in opposite directions. What would be the acceleration of this object if it has a mass of 100 kg?
A) 0.03 m/s2
B) 0.09 m/s2
C) 0.3 m/s2
D) 0.9 m/s2
The answer is A 0.03 m/s2.
4.4.12
Think of it! Identify as many pairs of action-reaction force pairs in the diagram.
The truck/tractor is driving forward, and the person is straining to hold on to the rope. The is resisting being pulled and his feet are going forward while the elephant goes backwards. The tires go forward and the rope is resisting.