Newtons Laws
If velocity is constant, acceleration = ______
0
Energy can transform from one form to another form which means that the amount of energy in the universe (does/does not) change.
Does not
What is the equation for the work done by gravity and the work done by a spring?
Hint: same thing as GPE and SPE
- delta GPE= Wgravity
-delta SPE = Wspring
what is the difference between speed and velocity?
velocity uses displacement
speed uses path length
What is perfectly inelastic collisions?
Elastic?
Glancing?
(tell me where two blocks go)
they move in the same direction after collision
opposite direction
3D
The vector sum of all external forces = _____ force
Net force
Mechanical Energy is associated with the obj's _____ and _____.
Which energy is associated with KE and PE?
KE is motion
PE is position
As a ball goes up the PE and KE?
As a ball goes down the PE and KE?
(increases/decreases)
increases, decreases
decreases, increases
what is velocity?
what is acceleration?
`
displacement over time
velocity over time
Provide the conversion from radians to degrees and vice versa.
radians x 180/pi
degrees x pi/180
Using Newton's Second Law, what do you know about force and acceleration when you increase mass?
When mass increases, acceleration decreases because the force is divided by mass (high mass, higher denominator)
What is the definition of work?
Equation?
measure of E transfer when obj is moved over distance by external force... (when force on block moves it over x, the force is doing work on the block)
W=F x cos () x X
Conservative force is?
energy that is recovered (has PE)
What is the initial velocity? (neg, pos, 0)
1) ball dropped
2) ball thrown down
3) ball thrown up
4) apex
0
-
+
0
Given vectors: F1 and F2, what is the equation to find net force?
Fnet= ((F1x+F2x)2 + (F1y+F2y)2)^(1/2)
What does the work energy theorem state?
Wnet done to obj changes its KE
Wnet= change in KE
F & X same direction = +
opp direction= -
perpendicular= 0
nonconservative force is?
when Fnc is present and ME is NOT constant which changes the initial energy and the final energy
If the initial velocity of a ball that is thrown up in the air off the top of a cliff is 4 m/s then what is the velocity of the ball as it reaches where you initially threw it?
-4 m/s
A 30kg block is held up by a rope connected to a scale. The rope is directly above, runs vertically from the middle of the block, and has a tension of 200 N. What does the scale read (weight)?
94.3 N
A block is dropped from a height of 5m and travels 20m (frictionless) to get to the bottom. The same block is dropped from a height of 5m but travels 40m (frictionless) to get to the bottom. Does the block have the same speed at the bottom or is one faster?
same speed
Work done by a nonconservative force changes the _____ energy. This means that Wnc=_____.
mechanical
delta ME
Wnet= delta KE
What is the resultant vector of vector A and B?
(equation)
R= square root of (Ax +Bx)2 + (Ay +By)2