I. Net Force:
→ Click the “Net Force” tab.
→ Check the”sum of forces” and “values” in the top right box.
→ Complete the Net Force Table & follow the action for setting up the investigation.
II. Net Force Table:
Directions for Set-Up
Before Pressing Go, which way do you think the cart will move? (None, Right, Left)
Why does the cart move that way?
What is the sum & direction of the forces?
(example: 70 Left)
Place 1 small blue guy on the very end of the left rope & 1 small red guy on the very end of the right rope
Before pressing Go, the cart will move to the right. This is because there is a greater net force acting on the cart in the right direction.
The cart moves to the right because the net force acting on it is greater in that direction. The net force is determined by adding up all the individual forces acting on the cart.
Initially, when only one small blue guy is placed on the left rope and one small red guy is placed on the right rope, the sum of the forces is 0. There is no net force acting on the cart, so it remains stationary.
Place the medium blue guy on the very end of the left rope & 1 small red guy on the very end of the right rope
When the medium blue guy is placed on the left rope and one small red guy is placed on the right rope, the sum of the forces is still 0. There is no net force, and the cart remains stationary.
Place the big blue guy on the very end of the left rope & add all 4 of the red guys to the right rope
III. Net Force Questions:
1. If you have an equal amount of force on both sides of the tug of war cart, what happens every time? Explain Why.
Type Answer HERE:
2. A student wanted to investigate changing the mass of a cart that you can push. The student pushed both carts with a force of 200 Newtons. If one cart has a mass of 100kg and the other cart a mass of 50kg, what results would the student expect to see as far as how fast each cart moved in comparison with one another?
Type Answer HERE:
3. A scientist wanted to move a golf ball and a bowling ball to both reach 15 mph. What would the scientist have to do differently for the bowling ball than the golf ball to reach his goal?
Type Answer HERE:
The Moving Man LAB
Instructions: Carefully read the directions to complete the virtual tasks in order. Then answer each of the questions given.
-Grab the man and drag him to 4 meters.
-Wait for 2 seconds and then grab the man and take him to the house.
-Wait for 2 seconds and then grab the man and return him to 0 meters.
-Stop the simulation.
Your Screen should look similar to this:
→ Now use the phet and the image above to answer the following questions below.
V. The Moving Man Questions:
4. Each time the man stopped and took a break, what happened to the line on the Position-Time Graph (Blue Graph). Explain why.
Type Answer HERE:
5. Each time the man stopped and took a break, what happened to the line on the Velocity-Time Graph (Red Graph). Explain why.
Type Answer HERE:
6. What happened to the line on the Position-Time Graph (Blue Graph) when the man returned to the 0 meters? Explain why.
Type Answer HERE:
7. Now click the reset all button. Now grab the man and move him as slowly as you can till he reaches the house. Notice the graph. Again, click the reset all button. Now grab the man and move him as quickly as you can till he reaches the house. Notice the graph. They should look similar to the following images:
Looking at the Position-Time Graph (Blue Graph), what do you notice about the slope of the lines on each graph? (Hint: Slope is the measure of the steepness of the line. Think about going up a hill. Some have a small slope that is like no big deal to climb. Then there are those that have a huge slope. It’s so steep that your eyes get big and you decide, I’m not doing that.) Explain what you are seeing in the graphs above.
Type Answer HERE:
VI. Analyzing the Data:
8.
Type Answer HERE:
The speed is constant.
The distance remains unchanged.
The direction of motion stays the same.
The speed gradually increases over time.
9.
Type Answer HERE:
The ball’s speed is increasing.
The ball’s speed is decreasing.
The ball’s motion is constant.
The ball’s motion is stopping.
10.
Type Answer HERE:
The object is experiencing acceleration.
The object is moving along a curved path.
The object has a negative acceleration.
The object moves at a constant speed.
11.
Type Answer HERE:
The velocity of the car remains constant throughout the journey.
The change in speed alone causes the velocity of the car to vary.
The change in direction alone causes the velocity of the car to vary.
The velocity of the car changes due to the change in speed and direction.
12. Which graph BEST represents the relationship between velocity and time for an object that accelerates uniformly for 2 seconds, then moves at a constant velocity for 1 second, and finally decelerates for 3 seconds?
Type Answer HERE:
READING & EVIDENCE IN SCIENCE
Instructions: Read the following and then answer the questions, using evidence from the text. Make sure answers use your own words.
Airbags-Science Life Savers
Airbags are safety devices designed to protect vehicle occupants during collisions by reducing the impact forces exerted on their bodies. The fundamental principle behind airbags is the concept of rapid inflation and deflation. When a collision occurs, sensors in the vehicle detect the sudden deceleration and send a signal to the airbag control unit. The control unit then triggers the inflation system.
The inflation system of an airbag consists of a solid-state propellant, typically sodium azide, and a mixture of other chemicals. Upon activation, an electric current passes through the propellant, causing it to rapidly decompose and release nitrogen gas. This gas inflates the airbag in milliseconds, allowing it to cushion the vehicle occupant's forward motion and prevent direct contact with hard surfaces, such as the steering wheel or dashboard. The airbag deflates quickly after inflation to allow the occupant to exit the vehicle safely. The entire process occurs in a fraction of a second, providing a protective barrier and reducing the risk of severe injuries, particularly head and chest injuries, during a collision.
VII. Reading & Evidence Questions:
13. Using the text above, how does an airbag work and why does it have to work so quickly?
Type Answer HERE:
14. How does inertia play a role during a car accident, and what tools are in place to keep us safe?
Type Answer HERE:
-Grab the man and drag him to 4 meters.
-Wait for 2 seconds and then grab the man and take him to the house.
-Wait for 2 seconds and then grab the man and return him to 0 meters.
-Stop the simulation.
Your Screen should look similar to this:
→ Now use the phet and the image above to answer the following questions below.
V. The Moving Man Questions:
4. Each time the man stopped and took a break, what happened to the line on the Position-Time Graph (Blue Graph). Explain why.
Type Answer HERE:
5. Each time the man stopped and took a break, what happened to the line on the Velocity-Time Graph (Red Graph). Explain why.
Type Answer HERE:
6. What happened to the line on the Position-Time Graph (Blue Graph) when the man returned to the 0 meters? Explain why.
Type Answer HERE:
7. Now click the reset all button. Now grab the man and move him as slowly as you can till he reaches the house. Notice the graph. Again, click the reset all button. Now grab the man and move him as quickly as you can till he reaches the house. Notice the graph. They should look similar to the following images:
Looking at the Position-Time Graph (Blue Graph), what do you notice about the slope of the lines on each graph? (Hint: Slope is the measure of the steepness of the line. Think about going up a hill. Some have a small slope that is like no big deal to climb. Then there are those that have a huge slope. It’s so steep that your eyes get big and you decide, I’m not doing that.) Explain what you are seeing in the graphs above.
Type Answer HERE:
VI. Analyzing the Data:
8.
Type Answer HERE:
The speed is constant.
The distance remains unchanged.
The direction of motion stays the same.
The speed gradually increases over time.
9.
Type Answer HERE:
The ball’s speed is increasing.
The ball’s speed is decreasing.
The ball’s motion is constant.
The ball’s motion is stopping.
10.
Type Answer HERE:
The object is experiencing acceleration.
The object is moving along a curved path.
The object has a negative acceleration.
The object moves at a constant speed.
11.
Type Answer HERE:
The velocity of the car remains constant throughout the journey.
The change in speed alone causes the velocity of the car to vary.
The change in direction alone causes the velocity of the car to vary.
The velocity of the car changes due to the change in speed and direction.
12. Which graph BEST represents the relationship between velocity and time for an object that accelerates uniformly for 2 seconds, then moves at a constant velocity for 1 second, and finally decelerates for 3 seconds?
Type Answer HERE:
READING & EVIDENCE IN SCIENCE
Instructions: Read the following and then answer the questions, using evidence from the text. Make sure answers use your own words.
Airbags-Science Life Savers
Airbags are safety devices designed to protect vehicle occupants during collisions by reducing the impact forces exerted on their bodies. The fundamental principle behind airbags is the concept of rapid inflation and deflation. When a collision occurs, sensors in the vehicle detect the sudden deceleration and send a signal to the airbag control unit. The control unit then triggers the inflation system.
The inflation system of an airbag consists of a solid-state propellant, typically sodium azide, and a mixture of other chemicals. Upon activation, an electric current passes through the propellant, causing it to rapidly decompose and release nitrogen gas. This gas inflates the airbag in milliseconds, allowing it to cushion the vehicle occupant's forward motion and prevent direct contact with hard surfaces, such as the steering wheel or dashboard. The airbag deflates quickly after inflation to allow the occupant to exit the vehicle safely. The entire process occurs in a fraction of a second, providing a protective barrier and reducing the risk of severe injuries, particularly head and chest injuries, during a collision.
VII. Reading & Evidence Questions:
13. Using the text above, how does an airbag work and why does it have to work so quickly?
Type Answer HERE:
14. How does inertia play a role during a car accident, and what tools are in place to keep us safe?
Type Answer HERE:
13. An airbag works by rapidly inflating and deflating in order to reduce the impact forces exerted on the bodies of vehicle occupants during collisions. When a collision occurs, sensors in the vehicle detect the sudden deceleration and trigger the inflation system. The inflation system uses a solid-state propellant, typically sodium azide, which decomposes and releases nitrogen gas upon activation. This gas inflates the airbag in milliseconds, providing a cushion to the occupant's forward motion and preventing direct contact with hard surfaces. The airbag then deflates quickly to allow the occupant to safely exit the vehicle. The airbag has to work quickly in order to provide a protective barrier and reduce the risk of severe injuries, particularly head and chest injuries, during a collision.
14. Inertia plays a role during a car accident because it is the tendency of objects to resist changes in their state of motion. When a car suddenly stops or changes direction during a collision, the occupants inside the car continue to move in their original direction due to their inertia. This can result in injuries as they collide with the interior of the car, such as the steering wheel or dashboard. To keep us safe, airbags are in place to cushion the forward motion of the occupants and prevent direct contact with hard surfaces. The rapid inflation and deflation of the airbag helps to reduce the impact forces exerted on the bodies of the occupants, minimizing the risk of severe injuries.
I. Net Force:
To find the net force of an object, follow these steps:
1. Click the "Net Force" tab.
2. Check the "sum of forces" and "values" in the top right box.
3. Complete the Net Force Table and follow the instructions for setting up the investigation.
II. Net Force Table:
Directions for Set-Up:
1. Before pressing Go, predict which way the cart will move. (None, Right, Left)
2. Explain why you think the cart will move that way.
3. Determine the sum and direction of the forces. For example: 70 Left.
4. Place one small blue guy on the end of the left rope and one small red guy on the end of the right rope.
5. Before pressing Go, state your prediction that the cart will move to the right because there is a greater net force acting on it in that direction.
Explanation: The cart moves to the right because the net force acting on it is greater in that direction. The net force is determined by adding up all the individual forces acting on the cart. Initially, when only one small blue guy is placed on the left rope and one small red guy is placed on the right rope, the sum of the forces is 0, resulting in no net force and the cart remaining stationary.
I. Net Force:
To complete the Net Force Table, follow these steps:
1. Click the "Net Force" tab.
2. Check the "sum of forces" and "values" in the top right box.
3. Write down the values in the Net Force Table.
4. Place 1 small blue guy on the very end of the left rope and 1 small red guy on the very end of the right rope.
5. Before pressing Go, predict the direction in which the cart will move (None, Right, Left).
6. Explain why you think the cart will move that way.
7. Determine the sum and direction of the forces acting on the cart.
II. Net Force Table:
1. If there is an equal amount of force on both sides of the tug of war cart, it will not move. This is because the forces cancel each other out, resulting in a net force of zero.
2. If the student pushes both carts with a force of 200 Newtons, the cart with a mass of 100kg will move slower than the cart with a mass of 50kg. This is because the heavier cart has a greater inertia, which resists changes in motion. Hence, it requires more force to move the heavier cart.
3. To make both the golf ball and the bowling ball reach 15 mph, the scientist would have to apply a greater force to the bowling ball. This is because the bowling ball has greater mass and therefore greater inertia, requiring more force to accelerate it to the same speed as the golf ball.
IV. The Moving Man:
4. Each time the man stops and takes a break, the line on the Position-Time Graph (Blue Graph) remains horizontal, indicating that the man is not changing his position. This is because when the man is not moving, his position remains constant.
5. Each time the man stops and takes a break, the line on the Velocity-Time Graph (Red Graph) drops to zero, indicating that the man's velocity becomes zero. This is because velocity is the rate of change of position, and when the man stops, there is no change in his position over time, resulting in zero velocity.
6. When the man returns to 0 meters, the line on the Position-Time Graph (Blue Graph) returns to the starting point. This is because the man has returned to his original position, resulting in zero displacement.
7. Looking at the Position-Time Graph (Blue Graph), the slope of the line is steeper when the man is moved quickly compared to when he is moved slowly. This indicates that the man is covering more distance in less time when moved quickly, resulting in a higher speed.
VI. Analyzing the Data:
8. The graph showing a constant speed best represents the given statement. This is because when an object is moving at a constant speed, the distance it covers over time remains unchanged.
9. The ball's motion is constant. This can be determined from the given statement, as there is no mention of the ball's speed increasing or decreasing.
10. The object moves at a constant speed. This is evident from the given statement, as there is no mention of the object experiencing acceleration or moving along a curved path.
11. The velocity of the car changes due to the change in speed and direction. This can be inferred from the given statement, as the change in speed and direction causes the car's velocity to vary.
12. Graph B best represents the relationship between velocity and time for an object that accelerates uniformly for 2 seconds, then moves at a constant velocity for 1 second, and finally decelerates for 3 seconds. This is because the graph shows an initial positive slope indicating acceleration, followed by a flat line indicating constant velocity, and then a negative slope indicating deceleration.
VII. Reading & Evidence Questions:
13. According to the text, an airbag works by rapidly inflating and deflating to reduce the impact forces exerted on vehicle occupants during collisions. It has to work quickly because collision events happen in a fraction of a second, and the rapid inflation of the airbag cushions and protects the occupant's forward motion, preventing direct contact with hard surfaces.
14. Inertia plays a role during a car accident because it is the tendency of an object to resist changes in its state of motion. In a car accident, when the vehicle suddenly decelerates, the occupants' bodies want to continue moving forward due to inertia. To keep us safe, tools like seat belts, airbags, and crumple zones in cars are in place. Seat belts restrain the body, preventing it from continuing to move forward. Airbags rapidly inflate to cushion the occupant's forward motion and prevent direct contact with hard surfaces. Crumple zones absorb and dissipate energy from the collision, reducing the impact forces experienced by the occupants.