Describing Motion
What do you call any push or pull on an object?
force
What does a horizontal (flat) line on a motion graph tell you about the motion of the object?
Object is still
Are forces balanced or unbalanced if an object stays at rest?
balanced
What type of acceleration can occur if forces are unbalanced?
all types
If a pencil was at rest on your desk, how long would it continue to stay at rest? (1st law)
until an unbalanced force moved it, such as you lifting it
When you describe an object's motion, you are usually describing it in relation to a fixed object or location, called a _____.
reference point
What does a straight line slanted upward tell you about the motion of an object?
Object is moving at a constant speed going away from the starting point.
Are forces balanced or unbalanced if an object accelerates?
unbalanced
What type of acceleration is illustrated by the blades of fan?
centripetal acceleration
If your pencil rolled across the floor, how long would it continue to roll at the same speed? (1st law)
until an unbalanced force changed its motion, such as friction with the floor
How do you calculate speed?
Speed = distance/time
If you are comparing two straight lines that are slanted upward on a motion graph, how can you tell which one represents a faster speed?
the line with a steeper slope is faster
Are forces balanced or unbalanced if the net force equals 0N?
balanced
What type of acceleration is illustrated by a student driver pushing harder on a gas pedal?
positive acceleration
If you want to accelerate the motion of the door positively when you open it to enter my classroom, what do you need to do? (2nd law)
push harder (increase force)
If a bird flies for 2 seconds and covers a distance of 10 meters, what is its speed.
5 m/s
What does a line that is curved upward on a motion graph tell you about the motion of an object?
It is speeding up while moving away from the starting point
What is the net force on an object that is being pulled to the left at 15N and to the right at 12N?
3N left
What type of acceleration is illustrated by someone's heart as they cool down from exercising?
negative acceleration
If I get a new classroom door that is heavier, what will you have to do to your force to make it accelerate at the same rate as before? (2nd law)
Would the new door have more or less inertia than the original door?
push harder (increase force)
more
If a student completes 20 math problems in 5 minutes, what is her speed?
4 problems/min
If the beginning and ending coordinates of a flat line that is curved downward on a motion graph are (0,6) and (6,0), what does it tell you about the motion of an object moving ft/min?
The object starts 6 ft away and speeds up ending at the starting point after 6 min. Average speed=1ft/min
What is the net force on an object if it is being pushed northward with one force of 4N and another force of 6N?
10N northward
What would the line look like on a motion graph if an object moved at a constant speed of 20cm/s and then accelerated to a constant speed of 5cm/s moving away from the starting point?
it would be a straight line slanted upward that would then change to a flatter line slanted upward
When your action is to push on my door, what is the reaction? (3rd law)
door pushes back with equal force