Motion Basics
An object is in motion if its position/distance changes relative to a _______.
reference point or another object
What is the basic SI unit for measuring length?
A meter
What is the formula for speed?
distance divided by time
In the formula for acceleration, what do the Vf and Vi stand for?
Final velocity and Initial velocity
A car starts at 0 m/s and reaches 20 m/s in 5 seconds. What is the acceleration?
4 m/s2
Which is a better reference point? A tree or a moving bicycle and why?
A tree because a tree is station - which means not moving
How many meters are in 1 kilometer?
1000 meters
Velocity is speed in a given _____.
direction
Acceleration is the rate at which _____ changes.
velocity
A rocket goes from 10 m/s to 50 m/s in 8 seconds. What is the acceleration?
5 m/s2
This term describes how motion depends on your point of view.
Relative motion
Scientists use the SI system so they can share data _______.
globally
What tool in the car shows instantaneous speed?
the speedometer
What are the three ways an object can accelerate?
Increase speed, decrease speed and change direction
A car travels 50m in 2s, stops for 1s, then travels 50m in 2s. What is the average speed for the whole trip?
20 m/s
True or False - You need a reference point to prove that an object is actually moving.
TRUE
1 centimeter = ____ of a meter
0.01 or one hundredth
Why is velocity critical for air traffic controllers?
To avoid collisions and to know exactly where airplanes are headed
What is the standard unit of measurement for acceleration?
m/s2
A bike speeds up from 5 m/s to 15 m/s in 5 seconds. Find the acceleration.
2 m/s2
You are on a train. To your friend next to you, you are still. To the person outside, you are moving. What is this called?
Relative motion
Distance is defined as...
the length of the path between two points
Give an example of a velocity measurement for a plane flying towards Florida.
500 km/h South (Any speed + direction)
True or False: If a car is traveling at a constant speed of 60 m/h while driving around a sharp curve in the road, the car is not accelerating.
False - changing direction means accelerating
A runner is training on a track. They run the first 200 meters in 25 seconds. Then, they takes a break and run another 300 meters in 75 seconds. What was the runner's average speed?
5 m/s