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Choose the right quantity and unit for a gravity question: meters for distance, seconds for time, meters per second for speed, meters per second squared for acceleration, and newtons or pounds for weight.
Use what you learned in the previous lesson to solve real-world problems.
Set a starting point and track how an object’s position changes with time. Distinguish distance traveled from “how far from the start” using simple falling or rolling examples.
Check what you understood with a short quiz.
Turn a measured distance and time into an average speed. Reason through why a runner, cart, or falling object can have one average speed even while its speed changes during the trip.
Read acceleration as a change in speed over a time interval. Use everyday cases—speeding up, slowing down, and steady motion—to recognize when acceleration is present.
Trace what happens to a dropped object near Earth when air resistance is small: it gains about 10 meters per second of downward speed each second.
Estimate how far an object falls after 1, 2, or 3 seconds using the idea that its speed keeps increasing. See why fall distance grows faster than time, not in equal steps.
Compare a stone, a feather, and a crumpled paper ball to separate gravity’s downward pull from air resistance. Predict when shape and speed make falling objects deviate from the simple falling rule.
Read a position-time graph by looking at its slope: flat means not moving, a steady slope means steady speed, and a curve means changing speed. Connect each graph shape to a visible motion.
Read a speed-time graph for falling and non-falling motion. Use the graph’s height to identify speed and its tilt to tell whether the object is accelerating.
Use a simple motion table with time, position, speed, and acceleration columns. Fill in missing values from easy measurements and check whether the pattern looks like steady motion or falling motion.
Measure weight as the downward pull shown by a spring scale or bathroom scale. Compare common weight units and recognize that a scale reading depends on gravity acting on the object.
Use a balance to compare two objects without needing to know their exact weights. Reason through why equal pulls on both sides make the beam level and unequal pulls make it tip.
Review this chapter with practice based on your mistakes.