Chapter 3: Linear Motion Flashcards
A car is driving at a steady 15 m/s around a circular track on level ground. Which statement about the car’s velocity and spreed is accurate?
The car’s speed is constant, but the velocity is changing
When we sit in a bus that is traveling down the road, we would describe ourselves as not moving, but a person sitting on a bench would say that we are in motion. This is an example of:
Relative Motion
Instead of dropping a ball, you throw a ball directly downward. After releasing the ball, what is the magnitude of its accelerations?
9.8 m/s^2
A ball is thrown straight upward. What is the velocity of the ball at the top of its ascent?
Zero
Galileo said the steeper the slope of an incline plane, the greater the acceleration of the ball. What is the magnitude of the ball’s acceleration if it falls vertically?
9.80
The reading on a car’s speedometer is a measure of its
Instantaneous speed
When dropped, a ball will
Fall a farther distance during the second than during the first second
When you throw a ball directly upward, what is true about its acceleration?
The ball’s acceleration is always directed downward
- Acceleration
The rate of change in velocity
- Velocity
How fast and in what directions an object covers a distance
- Distance
How far something travels
- Speed
How fast an object covers a distance
To define the position of an object in a plane, you need to measure
The object’s distance from a reference point and its angle measured from a reference line
A skateboarder is traveling down the sidewalk at a rate that does not change
The skateboarder is moving at a constant speed
What is true about an object that is in free fall
1) During each second of free fall, the object gains approximately 10 m/s in velocity
2) It accelerates with a magnitude of 9.8 on Earth
3) The acceleration is dependent on the amount of gravity
What throwing a ball upward, what is the magnitude of its acceleration at the top of its ascent?
9.8 m/s^2
Which of the following is classified as an acceleration?
1) Going around a curve at a constant speed
2) A decrease in velocity
3) An increase in velocity
When you throw a ball directly upward, what is true about its acceleration?
The ball’s acceleration is always directed downward
If a stone is thrown upward with a velocity of 30 m/s, at what velocity will it return to your hand?
-30 m/s
Of the following choices, which is the best description of g?
“g” is the magnitude of the acceleration due to the force of gravity
A car is traveling in an eastward direction, and for every second it travels the car cover less distance. What is the direction of the car’s acceleration vector?
Westward
Which of the following objects is considered to be in the free fall?
A hammer that is tossed upward by an astronaut on the moon (where there is no atmosphere)
When you drop a ball, what is true about its motion?
It falls and increases in speed at a rate of 9.8 m/s every second
If an object’s acceleration vector point in the same direction as its instantaneous velocity vector then you can conclude:
The object is speeding up
You are going to swim across a stream with a rapid current. You start swimming, aiming at a large tree directly across from you. You end up
Downstream from the tree
A car is traveling down the road, and for every second its travels, the car covers less distance. This mean that:
The car is slowing down
Which of the following are true about a car traveling at 50 km/hr in a circle?
1) The car has a constant speed
2) The car has a changing velocity
3) The car is accelerating
If an object’s acceleration vector points in the “opposite” direction of the instantaneous velocity vector, then you can conclude:
The car is slowing down
