Math Skills
vector
Displacement over time is equal to this...(be precise)
AVERAGE velocity
If a question talks about forces these might be your first two steps.
1) FBD
2) F=ma
The major law or concept for this unit is called this and the starting equation is that.
Conservation of Energy
Ei=Ef
The relationship that between linear and rotational values ( ex. displacement and angular displacement) relies on this
radius
K + v2 = 0.5x2 + Z This expression solved for x is
x = sqrt[2(K+ v2 - Z)]
The accelerations of a projectile in free fall is always ax = ____ and ay = ______
0 m/s2 and -9.81m/s2
N3L
A rollercoaster at the top of its path has no velocity. It starts with this type of energy and as it travels to the bottom of the path it converts into this type.
PEg to KE
A mass is attached to a string that's wrapped around a pulley at rest. The pulley has a rotational inertia of 0.75 kg m2 and is free to rotate about an axis through its center. Friction between the pulley and axle is negligible. At time t = 0 the mass is released and allowed to fall, rotating the pulley. The resulting torque on the pulley is 3.0 Nm.
The angular speed of the pulley after 1.8 s is
7.2 rad/s
T = Ia
a = 4.0 rad/s2
w = w0 +at
A man travels north 55 meters, east 25 meters, and south 20 meters. Only looking at his displacement vector, the direction he travelled in is.
35.5 deg NE
The displacement of the object between 0 to 4 seconds is
[GRAPH]
18 m
A 5.0-kg and a 10.0-kg box are touching each other. A 45.0-N horizontal force is applied to the 5.0-kg box in order to accelerate both boxes across the floor. Ignore friction forces and determine the acceleration of the boxes and the force acting between the boxes.
3 m/s2
Ftot = mtot*a
These are the 4 types of energy we have used in analyses of scenarios.
Elastic PE
Gravitational PE
KE
Rotational KE
Compare the torques of the two given wrenches and justify:
1: a force of F is applied at a distance R from the axis.
2: A force 3F is applied a distance R/3 from the axis
They are equal because torque is proportional to force and radius
Convert 25 km/hr to m/s.
6.94 m/s
A pedestrian walking on the side of the road travels north at 3 m/s (relative to a bird sitting in a tree). A car passes the pedestrian at a velocity of 20 m/s south (relative to that same bird). The velocity of the car relative to the walking pedestrian is this.
23 m/s
This is the FBD for the following statement: A block being dragged down a rough-surfaced incline.
Fg straight down
Fn perpendicular to surface
Ff parallel to surface up ramp
FT parallel to surface down the ramp
The work done to lift a 1500 kg amusement park ride to the top of its 50 meter drop is this.
735,750 J
A meter stick is being balanced and has ana xis of rotationaround its center of mass. Two mass are hung from the meter stick. Mass 1, 3.5 kg, at the 20 cm mark and mass 2, 2.8kg, at the 60 cm mark. Mass 3, 3 kg, would need to be hung at this cm mark.
75 cm
Left torque = Right torque
3.5*.3 = 2.8*.1+3*X
When a question says to justify you are expected to do this.
Use physics concepts and laws (beyond equations) to support a claim.
A man jumps out of a plane and begins to fall towards Earth. Explain in detail why he uses a parachute to slow his descent.
I: Only gravity acts on him and he is accelerating towards Earth (speeding up)
II: the parachute applies an upwards force on the diver causing his acceleration to decrease or even change direction. If his acceleration is in the opposite direction of his velocity he will slow.
Two blocks are attached by a string that is wrapped over a pulley (basic atwood machine). Mass 1, 3 kg, is hanging on the left side while mass 2, 4.5 kg, is hanging on the right side. Counterclockwise is the positive direction in this case. The acceleration of the blocks is equal to this.
-1.96 m/s2
A car with mass m is traveling with velocity v1 at the top of a tall hill with height h. The derived equation for the velocity of the car at the top of the hill in terms of h,v2, m, in is this.
sqrt(v22 - 2gh)
A carousel—a horizontal rotating platform—of radius r is initially at rest, and then begins to accelerate constantly until it has reached an angular velocity ω after 2 complete revolutions. the angular acceleration in terms of ω, r, and any physical constants is
ω2/(8pi)
ω2 = ω02 +2a*theta
theta = 2 rev* 2pi