Speed & Velocity
A car drives 10 mph for 20 min. How far did the car travel?
2 miles.
Speed = Distance / Time.
10 mph = x / 20 min
(10 mph = 60 min in 1 hr = 1 mile every 10 min)
1 mile/10 min [20 min] = 2 miles driven
What is a force?
A push or a pull.
Forces can be balanced or unbalanced and can be used to demonstrate and calculate relationships between force, motion and energy.
What can we find with a distance vs time graph?
The speed of an object
If 20N of force are pushing to the left and 20N of force are pushing to the right, which way will the box move?
Neither way. It is a balanced or net zero force.
What is Newton's 1st Law of Motion?
Law of Inertia
An object at rest stays at rest and an object in motion stays in motion until acted upon by an unbalanced force.
How is speed different from velocity?
Speed = magnitude
Velocity = magnitude + direction
What is gravity?
A force that pulls objects to the Earth.
What goes on the x and y axis? What goes above the graph?
X axis = time unit
Y axis = distance unit
Above = a title
If someone is pushing with 50N of force to the right and the other person is pushing with 10N of force to the left, which way will the box go?
To the right, because there is more force pushing that way.
What is Newton's 3rd Law of Motion?
For every action there is an equal and opposite reaction.
What is the average speed of a cow that walks east 60 meters in 90 seconds? (Remember, the units must be m/s or km/hr)
.7 m/s
What is friction?
A force that acts against moving objects.
What does a distance vs time graph with a straight (linear) line indicate about a moving object?
It's moving at a constant speed
If Spongebob was pushing a crabby patty to the left and plankton was pushing it to the right, which way would it go and why?
To the left, because Spongebob is stronger than plankton and able to generate a greater force.
What is Newton's 2nd Law of Motion?
f = m x a
The heavier the mass of an object, the harder it is to move and/or stop the object from moving.
Why is a frame of reference important when describing the speed, velocity or acceleration of an object?
Whether or not you perceive an object to be moving depends on your point of view, or point of reference. An object is in motion if it changes position relative to a reference point. A reference point is a place or object used for comparison to determine if something is in motion.
What is net force?
Net force is the calculation of all forces acting on an object.
What does a horizontal line in a time-velocity graph indicate?
No slope on a velocity graph indicates that the object is at rest (no movement).
If two people are pushing a box to the right and each person is putting forth 20N of force. Which way will the box move and with how much force will it be moving?
To the right with 40N worth of force.
A person flying through the windshield in a car crash is an example of which law of motion?
Newton's 1st Law
What is the velocity of an object that moves east for 6 seconds at 100 m/s, stops for 5 seconds, and then continues along the same path east for 10 seconds at 50 m/s?
7.14 m/s east
What two forces act upon leaves falling from trees that result in a winding, circular path to the ground?
Gravity and air resistance.
Gravity causes objects to accelerate downward, whereas air resistance acts in the direction opposite to the motion and reduces acceleration
What does a horizontal line on an speed vs time graph indicate?
The object is traveling at a same (constant) speed
What are the rules for calculating net force?
Same direction = add (+)
Opposite direction = subtract (-)
A rocket ship blasting into space is an example of which law of motion?
Newton's 3rd Law of Motion