Physics Chapter 3
directed downward
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
15m/s
A car accelerates from rest at 3 meters per second per second. What is its speed 5 seconds after it starts moving?
the velocity and acceleration are both not 0
A car travels around in a circular path at a constant speed. Which of the following statements is true?
60m/s
An object is in free fall. At one instant, it travels at about 50 meters per second. Exactly one second later, the magnitude of its downward velocity is
vector quantity
Any quantity that requires both magnitude and direction to be fully described is called a(n)
its velocity increase
As an object freely falls
the same
Drop a rock from a 5-meter height and it accelerates at 10 m/s/s, striking the ground one second later. Drop the same rock from a height of 2.5 meters and its acceleration of fall compared to the 5-meter height is
square
Galileo discovered that the distance a uniformly accelerating object travels is directly proportional to the ___ of the time traveled
decrease the acceleration due to gravity
Galileo's use of inclined planes allowed him to effectively
360 km/s
If a car increases its velocity from zero to 60 km/hr in 10 seconds, its acceleration is
slope
If we graph the motion of a tangerine moving at a constant speed on a position-time graph, the magnitude of its speed can be determined by computing the ____ of the line. (Hint: Ski ______ )
9.8 m/s^2
If you drop an object, it will accelerate downward at a rate of 9.8 meters per second per second. If you instead throw it downwards, the magnitude of its acceleration (in the absence of air resistance) after leaving your hand will be
acceleration
Motion that you can feel is called _________.
constant
Speed in which equal distances are traveled in equal time intervals is called
31
Suppose you are going on a long bicycle ride. You ride 1 hour at exactly 5 mi/hr. Then you ride 3 hours at exactly 4 mi/hr and then 2 hours at exactly 7 mi/hr. How many miles did you ride? Pretend instantaneous acceleration or deceleration between different parts of your ride (that is, no time passes, for example, when you change from 5 mi/hr to 4 mi/hr).
100m/s
Ten seconds after starting from rest, a freely falling object will have a final velocity given by...downward at about
velocity
The amount of distance traveled by an object in a certain amount of time in a particular direction is called the object's
speed
The amount of distance traveled by an object in a certain amount of time is called the object's
acceleration
The change in an object's velocity in a certain amount of time is called the object's
-9.8m/s^2
The exact (to the first decimal place) numerical value and units for acceleration due to gravity on earth is ______.
acceleration
The slope of a line on a velocity-time graph tells us the ________ of an object in motion. (Remember: Slope is rise/run. What would that give you if applied to a velocity-time graph?)
instantaneous speed
The speed of an object at a particular moment of time, say for a brief moment you look at your car's speedometer, is called
0
What is the acceleration of a car that maintains a constant velocity of 100 km/hr for 10 seconds?
velocity is zero and its acceleration is about -10 m/s^2
When a rock thrown straight upward gets to the exact top of its path, its
acceleration
_______ is the kind of motion an object will undergo when a net force is applied to it
acceleration
disregarding air resistance, objects fall at a constant
10m/s
during each second of fall an object gains a speed of about ___ meters per second
miles/hour
english/imperial measurement for the speeds of motor vehicles
6 seconds
paintball is shot straight up at a velocity of 60 m/s. Assuming that air resistance can be ignored, the time it takes to reach the top of its path is about
scalar quantity
quantities that require only magnitude to be fully described
time
speed is divided by a unit of
distance
speed is measure in terms of a unit of
25m/s
the average speed a cheetah that sprints 100 meters in 4 seconds
20km/hr
the average speed of a horse that gallops a distance of 10 kilometers in a time of 30 minutes
60km
the distance a car will travel with an average speed of 60 km/hr for one hour
total distance/total time
the formula for average speed
kilometers/hour
the metric measurement for the speeds of motor vehicles
acceleration
the rate at which the velocity of an object changes with respect to an interval of time is
instantaneous
the speed an object has at any one moment is call its _____ speed
free fall
things fall because of the force of gravity, the falling object is in this state
speed and direction
velocity depends on knowing this of a moving object
equal
when something moves at a constant velocity or constant speed, than ____ distances are cored in equal intervals of time