Unit 1: Linear Motion
What is the difference between distance and displacement?
Distance is the total path taken and Displacement is the shortest path in a straight line between 2 points
Which changes based on where you are in the universe, mass or weight?
Forces always occur in _____ and they will always be ______ and _______.
pairs equal & opposite
If I am holding a 300lbs box above my head, am I doing work? Why or why not?
No, because work is a force exerted over a distance, and since we are holding the box in place it is not exerting it over a distance.
What are the units for acceleration?
m/s2
What type of speed does a police officer's radar gun pick up?
Instantaneous Speed
What is Newton's 1st Law? For double points, what is another name for the law?
An object will maintain its constant velocity unless acted upon by an unbalanced force.
The law of inertia
A fly splatters against the windshield of a moving car. on the highway. The acceleration of the car is __________________ the acceleration of the fly.
less than
If I am lifting a 300lbs box above my head, am I exerting power? Why or why not?
Yes, because you are doing work to lift the box up, and it is happening in a certain amount of time
What are the units for force (using the word, not just the symbol)?
Newtons
A sheet of paper and a car are dropped at the same time. With no air resistance, which one hits the ground first AND why?
They hit the ground at the same time because they have the same acceleration due to gravity
What are the 2 things the acceleration of an object depends on?
Net force acting on an object
Mass of the object
During the egg drop lab, we were looking at impulse. Which variable did we try and change to try to manipulate/change to stop the egg from cracking?
Time (stopping time)
I am driving down the street and the tires on my car are heating up due to what type of energy? Double points if you can mention what force it is that causes this to happen.
Thermal energy / force of friction
What is the unit for work/energy? Write down the variable symbol and its name.
Joules, J
Draw a position vs time graph (with correct axis labels) of an object that goes forward, stays still, then moves backwards, part the starting point?
Draw on board
What do each of these forces represent?
Fa, Fg, FN, FT, FF
Fa = force applied
Fg = force of gravity (weight)
FN = normal force
FT = tension force
FF = force of friction
What are the 2 types of conservation of momentum equations, and give real life examples of both?
Elastic - anything where 2 objects collide and do not stay together after
Inelastic - anything where 2 objects collide and end up together after
What types of energy are height and velocity related to (which equations would you use to solve for them)?
Height = potential energy (PE = m*g*h)
Velocity = kinetic energy (KE = 0.5*m*v2)
What are the variables and units for power?
Variable (P) / unit (watts/W)
How fast was an object's initial velocity if it traveled from 2560 meters in the air to the ground in 16 seconds? Need to see FULL GUESS!
G: x=2560 m, t=16s, g=10m/s^2
U: vi = ?
E: x = (Vi)(t) + (1/2)(g)(t)
S: 2560 = (vi)(16) + (1/2)(10)(16)
S: vi = 80 m/s
A 10 kg box is resting on a horizontal surface. The coefficient of friction between the box and the surface is 0.3. An applied force of 30 N is applied horizontally to the right.
- Identify the forces:
- Draw the Free Body Diagram (FBD):
- Calculate the net force:
Drawing on board
A 5 kg momma bird and 2 kg baby bird are together in their nest (at rest). The mom wants her child to learn to fly, so she pushes the baby out of the nest. The baby moves away at 1 m/s. WHat is the final momentum of the baby bird?
2 kg•m/s
Tony Hawk, who has a mass of 78 kg is trying out snowboarding instead of skateboarding and wants to know about the energy involved. He is starting in Colorado on a mountain that is 14,500 m. halfway down the mountain, what is the Tony’s total energy?
11,310,000 J
Write down 2 units we can use to find impulse.
Force and time OR mass and change in velocity