On their summer vacation, a family is standing at a scenic overlook at the top of a tall cliff. Young Alice (age 2) tosses a rock over the edge and giggles as she watches it fall. Brother Darrell (age 8) thinks he can do better and hurls another rock over the edge. Papa Billy chuckles, picks up a nice round rock, and flings it off the cliff as hard as he can.
1. In the picture to the right, draw the trajectory, or path, that each rock would take. Label the three trajectories “Alice”, “Darrell” and “Billy” (or just A, D and B).
2. What would happen if Billy could throw the rock as fast as a rocket? . Gizmo Warm-up: Which way does gravity pull?1. Use the slider to set the Velocity to 0.0 km/s (kilometers per second). Velocity is basically the same thing as speed, but has direction as well. In this case the pitcher is simply
dropping the ball. Click Play ( ).
2. Click Reset ( ) and drag the pitcher to several new positions. Click Play and watch him drop the ball each time. Sketch the pitcher and the trajectory of each ball on the diagram.
A. What do you notice?B. The ball is pulled by a force called gravity. In what direction does gravity always pull the ball? .
Activity A: How far does it go?
Get the Gizmo ready: Click Reset.1. Observe: Click Play and observe the ball’s trajectory. (Note:
The pitcher is very tall – about 1500 km (930 miles) tall!)
2. Predict: How would the trajectory of the ball change as the pitcher throws it harder and harder? Explain below, and draw several predicted trajectories on the diagram. .
3. Collect data: Throw the ball at velocities of 3, 5, and 7
km/s. If necessary, use the Fast forward button ( ) to speed things up and the “–” zoom control to see a larger area. For each throw, sketch and label the trajectory and record the Distance traveled in the table below.
6. Run Gizmo: Test 8 km/s and 9 km/s. (If you have a lot of spare time, try 10 km/s as well.) Use the “–” zoom control. What happens? .
Activity B:1. Observe: Look at the Planet mass and Planet radius of Venus. The mass of a planet is how much matter it contains. The radius of a planet is the distance from the center to the surface. Compared to Earth, what are the mass and radius of Venus?
Venus mass: × Earth’s mass Venus radius: × Earth’s radius2. Predict: Will the pitcher have to throw the ball faster or not as fast to send a ball into orbit around Venus?
3. Run Gizmo: Orbital velocity is the velocity needed to make a circular orbit. Use the Gizmo to find the orbital velocity of the ball on Venus. Make the orbit as circular as you can.
A. What is the orbital velocity on Venus? B. Do the same on Earth. What is the orbital velocity on Earth? C. Based on this, which planet do you think has stronger gravity, Venus or Earth?6. Extend your thinking: The escape velocity is the smallest velocity needed for the baseball to escape from the planet’s gravity and fly off into space, never to return. When the ball reaches escape velocity, the Distance traveled will read “infinity.
A. Which planet do you think has the lowest escape velocity? B. Use the Gizmo to test your prediction. Were you correct?1. What two things did you learn about the effect of gravity of an object from completing this Gizmo lab? (Please use complete sentences.)
2. What happens to the level of gravitational pull an object has as its mass increases? 3. What happens to the gravitational force if the distance between two objects increases?DOWNLOAD Student Exploration: Carbon Cycle Vocabulary : atmosphere, biomass, biosphere, carbon reservoir, carbon sink, fossil fuel, geosphere, greenhouse gas, hydrosphere, lithosphere, photosynthesis Prior Knowledge Questions (Do these BEFORE using the Gizmo.) In the process of photosynthesis , plants take in carbon dioxide (CO 2 ) from the atmosphere and water (H 2 O) from the soil. Using the energy of sunlight, plants build molecules of glucose (C 6 H 12 O 6 ) and oxygen (O 2 ). How do plants on Earth affect the amount of carbon in Earth’s atmosphere? Animals eat plants and produce carbon dioxide and water. How do animals affect the amount of carbon in Earth’s atmosphere? Gizmo Warm-up The Carbon Cycle Gizmo™ allows you to follow the many paths an atom of carbon can take through Earth’s systems. To begin, notice the black carbon atom in the Atmospheric CO 2 area, highlighted in yellow. The glowing blue areas represent possible locations the carbon atom could
DOWNLOAD Student Exploration: Calorimetry Lab Vocabulary : calorie, calorimeter, joule, specific heat capacity Prior Knowledge Questions (Do these BEFORE using the Gizmo .) The Latin word calor means “heat,” and meter comes from the Greek word meaning “to measure.” What do you think a calorimeter does? 2.Where have you heard the word calorie before? What do you think a calorie is? Gizmo Warm-up A calorimeter is an insulated container filled with a liquid, usually water. When a hot object is placed in the calorimeter, heat energy is transferred from the object to the water and the water heats up. Calorimeters can be used to find a substance’s specific heat capacity . You will use the Calorimetry Lab Gizmo™ to determine the specific heat capacities of various substances. 1. On the SIMULATION pane, select Copper . Use the slider to set its Mass to 200 g. Set the Water mass to 200 g. Check that the Water temp is set to 30.0 °C and the copper’s Temp
DOWNLOAD Student Exploration: Fan Cart Physics Vocabulary: acceleration, force, friction, mass, newton, Newton’s first law, Newton’s second law, Newton’s third law, velocity Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. Imagine a horse pulling a cart. What would happen to the speed of the cart if several bags of cement were added to the cart? 2.Suppose several more horses were hitched up to the same cart. How would this affect the speed of the cart? Although these questions may seem simple, they form the basis of Newton’s second law of motion. The Fan Cart Physics Gizmo™ can be used to illustrate all three of Newton’s laws. Gizmo Warm-up The Fan Cart Physics Gizmo™ shows a common teaching tool called a fan cart. Place fan A on the cart and turn it on by clicking the ON/OFF button below. 1. Look at the blue lines coming from the fan. In which direction is the air pushed? 2.Press Play ( ) and observe the cart. In which direction does the ca