Definitions? 1
The property of an object to resist a change in angular motion.
What is angular inertia?
A rotating body will maintain a state of constant angular motion unless acted on by an external torque refers to _____.
What is Newton's first law?
In the equation for moment of inertia, which variable is most influential?
A gymnast dismounts the uneven parallel bars with some angular momentum about her transverse axis. Just after release, she is in a piked position. She then extends into a layout position before she lands. What happens to her moment of inertia and rotational speed (angular velocity)?
Her moment of inertia increases and she rotates slower (angular velocity decreases).
These are carnivorous plants with pitcher-shaped leaves, which act as passive pitfall traps for bugs.
What is a pitcher plant?
The quantity that describes angular inertia.
What is moment of inertia?
This law states that for every force exerted by one body on another, the other body exerts an equal force back on the first body but in the opposite direction.
What is Newton's third law?
Calculate the moment of inertia when an object’s mass is 12 kg and the mass is distributed 4 m from the axis of rotation.
192 kg*m2
What is an object's mass if we know the object's angular momentum is 8 kg*m2/s, the radius is 2m from its axis of rotation, and the angular velocity is 4 revolutions per sec?
m = 0.0795 or 0.08 kg
The head of this animal stays relatively still/in place even when its body is moved or rotated, as its eyes are locked in place in their sockets and can't move up/down or left/right thus limiting its ability to keep things in sight.
What is a chicken?
The product of inertia and angular velocity.
"The change in angular momentum of an object is proportional to the net external torque exerted on it, and this change is in the direction of the net external torque. The net external torque exerted on an object is proportional to the rate of change in angular momentum." is what law?
What is Newton's second law?
Sarean is driving through Illinois towards St Louis, and she approaches the part of the drive where there are seemingly hundreds of wind turbines in fields. She is bored so she decides to calculate the angular momentum of a wind turbine using the specs she, for some reason, knows. Based on a wind turbine with an angular velocity of 2 rad/s, a radius of 20 m, and a weight of 24,000lb, what is the angular momentum of the wind turbine she sees?
Hint: Hi = Iiωi = Ifωf = Hf and I = mk2
H = 8709062.869 kg*m2/s
Tony Hawk (body weight: 79kg) performs a front flip after skating up a half pipe to dismount off of his skateboard. His angular velocity at the beginning of his front flip was 25 rad/s. His angular velocity right before his feet hit the ground was 4 rad/s and his moment of inertia was 16kg*m2. What was his radius while tucked at the beginning of his front flip?
Hint: Hi = Iiωi = Ifωf = Hf and I = mk2
k=0.180m
This bird is considered the "watch dog" of the forests and has a pokemon-like call--it is named after the sound of the call it makes--the more "dees" at the end of its call the higher the threat level of its surroundings.
What is a chikadee?
A length measurement that represents howfar from the axis of rotation all of the object’s mass must be concentrated to create the same resistance to change in angular motion as the object had in its original shape.
What is radius of gyration?
This is the product of torque and the time that torque is applied.
What is angular impulse?
It's 2017, fidget spinners have blown up in popularity. You are testing two to determine which has the greater angular momentum before you make your purchase (because surely these are not a fad and you will use it forever). The purple one has a moment of inertia of 0.04 kg*m2 and angular velocity of 5730 degrees/s. The yellow one has a moment of inertia of 0.06 kg*m2 and angular velocity of 140 rad/s. Which one do you buy?
The yellow one!
Purple: 4 kg*m2/s
Yellow: 8.4 kg*m2/s
Sarean's dad exerts a torque of 6 Nm on a 60g wrench while trying to tighten a wheel bolt that is for some reason greased and spins (along with the wrench) upon torque applied. The wrench has a radius of gyration of 12 in. If this is the only torque we care about, what is the angular acceleration?
Hint: ƩTa = Iaαa, I=mk2, and Nm is kg*m2/s2 ALSO 1 in = 2.54 cm
a = 1076.391 rad/s2
These are the fibers that connect the valves in the heart to the papillary muscles in the heart.
What is chordae tendineae (or heart strings)?
This is when the sum of the forces acting on the object must be equal to 0 and the sum of all torques acting on an object is equal to 0.
What is static equilibrium?
It is the ______ that are equal and opposite, not the _____.
What is forces and effects?
During a trampoline routine, a gymnast is tumbling in the air at 20 rad/s in a tuck position. He then extends into a layout position and doubles his radius of gyration just before landing on the trampoline bed. How fast is his angular velocity at this instant, just before landing on the trampoline bed?
5 rad/s
A discus thrower exerts a torque of 5 Nm on a 2 kg discus. The discus has a radius of gyration of 10 cm. If this is the only torque exerted on the discus, what is its angular acceleration?
Hint: ƩTa = Iaαa, I=mk2, and Nm is kg*m2/s2
250 rad/s2
This is the name of the anastomotic ring of arteries at the base of the brain.
What is the circle of willis?