Science Ch. 19 Lesson 1 – Describing Motion
Average speed can be found using? Distance divided by time
A runner runs 400 meters in 40 seconds. Find the runner’s average speed in meters per second. Show your work. 10 pts. The runner’s average speed is 400m/40s = 10m/s
Can the speeds of these two bicyclists be the same? Can their velocities be the same? 5 pts. Their speeds can be the same but their velocities cannot, because they are riding in opposite directions.
You are riding in a car traveling at a speed of 20 mph. A truck traveling at 25 mph in the same direction passes you. Your car stops and a police van passes you going 25 mph. Which vehicle appears to be traveling faster to you? Why? The police van passing my stopped car appears to move faster because my frame of reference is different.
Science Ch. 19 Lesson 2 – Forces & Motion
The tendency of An object at rest to stay at rest is called? inertia
Who would skate faster, a person using in-line skates on smooth concrete or on grass? Why? The person skating on smooth concrete would skate faster because friction between the skates and smooth concrete is less than friction between the skates and grass
Newton’s ____________ law of motion states that for every action force, there is an equal and opposite reaction force.
_____________ has a mutually attractive force between objects that have mass.
Gravity is a weak force between two masses unless the masses are??? Very large
The pull of gravity on a mass is called its ________________.
What causes the weightlessness shown in this picture? The astronaut and the spacecraft are falling at the same rate.
The machine in the picture has an arm that moves around a pivot point called the??? fulcrum
The machines in this picture are examples of ____________ - class levers
Which simple machine would make it easiest to move a heavy object from the ground to the third floor of the a house? Explain why. 10 pts. The pulley system. It uses many sections of rope to share the load, so you need a smaller force to lift the object. Fixed pulleyMovable pulleyPulley System
Definitions for test Speed Velocity Acceleration Frame of reference Friction