1D Motion
Define the variables X, V, a, and t
Position, velocity, acceleration, and time
Which velocity is constant in a projectile motion problem?
Vx
If I took a dumbbell to the moon:
Its mass: Increases, decreases, or stays the same?
Its weight: Increases, decreases, or stays the same?
Mass will stay the same
Weight will decreases (things are "lighter" on the moon)
What energy does a cannonball have when it's shot in the air? (more than one)
Kinetic and gravitational potential energy
How do you convert an angle from degrees to radians? How do you convert an angle from radians to degrees?
degrees-->radians, multiply by 2π/360°
radians-->degrees, multiply by 360°/2π
An object is speeding up when velocity and acceleration are both _________
the same sign
Which trig function will help you find the value of the side "x"? (I will draw it on the board)
I don't know!!
Would a 5kg block being pushed along a road experience more, less, or the same amount of friction as a 10kg block being pushed along the same road?
The 5kg block would experience less friction than the 10kg block. Consider the equation Ff=μkN, where the 10kg block would have a greater value for N.
What happens when two cars collide in an elastic collision? What if it was inelastic?
In an elastic collision the cars bounce off each other.
In an inelastic collision they stick together.
I'm having trouble unscrewing a stuck bolt with a wrench. What are three physics-related factors I need to consider to help unscrew it?
1) A strong force
2) A 90 degree force angle
3) Applying the force as far from the bolt as possible
For a standard projectile motion problem, does ax stay the same or does it vary? What about ay?
ax=0
ay=-9.8m/s2
True or False: on a flat, non-inclined surface, an object's normal force is always equal to "mg"
False. The normal force from a surface is just whatever forces are pushing down on it, which can be greater or less than "mg". N would only be equal to mg when there are no other vertical forces acting on it.
When a problem asks "how much does the object compress the spring?" what energy will always be zero at that EF position?
Kinetic energy is zero when a spring is fully compressed
What are two cases where putting a force on a rotating beam would cause it to NOT rotate
1) putting a force on the pivot
2) Putting a force parallel to the beam (θ=0°)
When a car crashes into another car, what two values or variables are equal?
The positions of both cars are equal. This also occurs the moment two objects pass each other.
When asked to find the maximum height of an object in projectile motion, what variable value do we already know at that moment, without solving?
VY=0 at the top of an objects trajectory.
For a block on a slope inclined at angle θ, what is the component of the weight force that is perpendicular to the slope?
mgcos(θ)
How do you know when to use conservation of momentum, as opposed to conservation of energy in a problem?
You would use conservation of momentum when a crash or collision occurs.
Write Newton's seconds law (F=ma, or a=F/m) using the rotational equivalent variables,
(like how x=θ, v=ω, etc.)
τ=Iα
(torque = moment of inertia times angular acceleration)