CHAPTER 3 (PHYSICS)
If a projectile is fired straight up at a speed of 10 m/s, the time it takes to reach the top of its path is about
1 second
If a projectile is fired straight up at a speed of 10 m/s the total time to its starting position is about
2 seconds
If you drop an object it will accelerate downward at a rate of 9.8 meters per second squared. If you instead throw it downwards, its acceleration will be
9.8 meters per second squared
The difference between speed and velocity involves
Direction
In each second of fall, the distance a freely falling object will fall is
Increasing
While an object near the Earths surface is in free fall, its
Velocity increases
A car accelerates at 2 meters/s/s. Assuming the car starts from rest, how far will it travel in 10 s?
100 m
A horse gallops a distance of 10 kilometers in a time of 30 minutes. Its average speed is
20 km/h
An object at rest is near the surface of a distant planet starts to fall freely. If the acceleration there is twice that of the Earth, its speed one second later would be
20 m/s
A ball freely falling at 20 m/s will in the next second have a speed of
30 m/s
At one instant heavy object in air is moving upward at 50 meters per second. One second later its speed is approximately
40 m/s
In its first second of free fall, a dropped softball will fall a vertical distance of
5 m
One half second after starting from rest, a freely falling object will have a speed about
5 m/s
If a car accelerates from rest at 2 meters per second per second, its speed 3 seconds later would be about
6 m/s
If an object moves with constant acceleration, its velocity must
Change by the same amount each second
A ball tossed vertically upward rises, reaches its highest point and then falls back to its starting point. During this time the acceleration of the ball is always
Directed downward
A bullet is dropped from the top of the Empire State building while another bullet is fired downward from the same location. Neglecting air resistance, the acceleration of
Each bullet is 9.8 meters per second squared
A ball is thrown upwards and returns to the same position. Compared with its original speed after release, its speed when it returns is about
The same
It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft?
about 180 m.
If a freely falling object were somehow equipped with a speedometer, its speeding reading would increase each second by about
10 m/s
An object falls freely from rest on a planet where the acceleration due to gravity is 20 meters per second squared. After 5 seconds, the object will have a speed of
100 m/s
While youre 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
If a freely falling object were somehow equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s/s, the its speed reading would be increased each second by
20 m/s
Disregarding air resistance, objects fall with constant
Acceleration
Galileo discovered that when air resistance can be neglected, all objects fall with the same
Acceleration
If an object falling freely were somehow equipped with an odometer to measure the distance it travels, then the amount of distance it travels each succeeding second would be
Greater than the second before
A speedometer normally measures
Instantaneous speed
When a rock thrown straight upwards gets to the exact top of its path its
Velocity is zero and its acceleration is about 10 meters per second per second.
A car maintains a constant velocity of 100 km/h for 10 seconds. During this interval its acceleration is
Zero
A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is
Zero
And object covers a distance of 8 meters in the first second of travel, another 8 meters again during the third second. Its acceleration in meters per second per second is approximately
Zero