Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
CA. Physics (Ch.3)
CA. Physics (Ch.3) actual questions
| Question | Answer |
|---|---|
| While you're in a bus that moves at 100 km/h you walk from the back to the front at 10 km/h. What is your speed relative to the road outside? | 110 km/h |
| Galileo's definition of speed was a breakthrough because he is acknowledged to be the first to consider | distance covered and time |
| A speedometer normally measures | instantaneous speed |
| The difference between speed and velocity involves | direction |
| Something that accelerates undergoes a | change in velocity per unit time (m/s/s) |
| Galileo discovered that when air resistance can be neglected, all object fall with the same | acceleration |
| When we're talking about how quickly "how fast" changes, we're talking about | acceleration |
| A ball freely falling at 20 m/s will in the next second have a speed of | 30 m/s |
| In its first second of free fall, a dropped softball will fall a vertical distance of | 5m |
| All motion is | relative |
| Velocity is speed with | direction specified |
| Conversion factors have a numerical value of | 1 |
| Which is a conversion factor for 1 hour? | 3600 seconds |
| Acceleration is the rate at which you change | how fast |
| A car increases its velocity by 60 miles per hour in ten seconds. Its acceleration is | 6 miles per hour per second |
| The forces that act on an object in free fall | are gravitation only |
| An object in free fall accelerates at g. Ignoring air resistance, what is the acceleration after being thrown downward? | still g |
| In this lesson, what does the symbol y represent? | Falling distance |
| Which rule(s) is used for combining velocities? | Vector rules |
| When combining a pair of velocities at an angle to each other, a useful rule involves | parallelograms |
| An airplane flying at 100 km/h directly into a 100 km/h headwind has a speed relative to the ground of | 0 km/h |
| Speed: | How fast an object moves; the distance traveled per unit of time. |
| Instantaneous Speed: | The speed at any instant. |
| Average Speed: | The total distance traveled divided by the time of travel. |
| Velocity: | An object’s speed and direction of motion. |
| Vector Quantity: | A quantity that has both magnitude and direction. |
| Scaler Quantity: | A quantity that has only a magnitude, not a direction. |
| Acceleration: | The rate at which velocity changes with time; the change in velocity may be in magnitude, or direction, or both. |
| Free Fall: | Motion under the influence of gravity only. |
| What two units of measurement are necessary for describing speed? | Distance and time |
| What is the main difference between speed and velocity? | Velocity needs direction, speed doesn't |
| If a car moves with a constant velocity, does it also move with a constant speed? | Yes, because constant velocity requires constant speed in the same direction |
| When can acceleration be defined as the time rate of change of speed? | When the object is moving in the same direction (doesn't change its velocity) |
| What is the acceleration of a car that maintains a constant velocity of 100 km/h for 10 s? | Zero |
| What did Galileo discover about the amount of speed a ball gained each second when rolling down an inclined plane? What did this say about the ball’s acceleration? | The ball rolls with constant acceleration. The ball gained the same speed every second. |
| What relationship did Galileo discover about a ball’s acceleration and the steepness of an incline? What acceleration occurs when the plane is vertical? | The steeper the incline, the greater the acceleration. On a vertical incline, the ball is in free fall. |
| What is the gain in speed per second for a freely falling object? | 10 m/s |
| The acceleration of free fall is about 10 m/s2 . Why does the seconds unit appear twice? | The second unit appears twice in the free-fall acceleration shorthand notation, once for the unit of speed and again for the time interval during which the speed changes. |
| What relationship between distance traveled and time did Galileo discover for freely falling objects released from rest? | Galileo found that the distance a uniformly accelerating object travels is proportional to the square of time. The distance traveled by a uniformly accelerating object starting from rest is: Distance traveled = ½ (acceleration x time x time) |
Created by:
RosalynCranney