Answer:
59.4 meters
Explanation:
The correct question statement is :
A floor polisher has a rotating disk that has a 15-cm radius. The disk rotates at a constant angular velocity of 1.4 rev/s and is covered with a soft material that does the polishing. An operator holds the polisher in one place for 4.5 s, in order to buff an especially scuff ed area of the floor. How far (in meters) does a spot on the outer edge of the disk move during this time?
Solution:
We know for a circle of radius r and θ angle by an arc of length S at the center,
S=rθ
This gives
θ=S/r
also we know angular velocity
ω=θ/t where t is time
or
θ=ωt
and we know
1 revolution =2π radians
From this we have
angular velocity ω = 1.4 revolutions per sec = 1.4×2π radians /sec = 1.4×3.14×2×= 8.8 radians / sec
Putting values of ω and time t in
θ=ωt
we have
θ= 8.8 rad / sec × 4.5 sec
θ= 396 radians
We are given radius r = 15 cm = 15 ×0.01 m=0.15 m (because 1 m= 100 cm and hence, 1 cm = 0.01 m)
put this value of θ and r in
S=rθ
we have
S= 396 radians ×0.15 m=59.4 m
A heat pump has a coefficient of performance of 7.05. If the heat pump absorbs 20 cal of heat from the cold outdoors in each cycle, find the heat expelled to the warm indoors. Answer in units of cal. I believe COP (heating mode) : 7.05 and COP = Qh/W Qc = 20 cal so I have to find Qh= ? cal I dont know an equation to put all this together? Please help, thank you.
Gate-control theory
<h3>What is Gate-control theory?</h3>
According to the Gate Control Theory of Pain, the spinal cord has a system that allows pain signals to be amplified in the brain before being processed at the spinal cord itself, or attenuated there.
The mechanism that allows or prevents the passage of pain signals is known as the gate. The gate may be open or it may be closed, one of two possibilities:
- When the gate is open, pain signals can enter and are delivered to the brain, where they are perceived as pain.
- If the gate is closed, pain signals will be prevented from ascending to the brain and won't be felt.
The administration of a non-noxious (soothing or light rubbing) stimulus can help engage the gate control mechanism and alleviate pain in those who are exposed to painful (noxious) stimuli.
Learn more about gate-control theory here:
brainly.com/question/15561467
#SPJ4
Answer:
<em>Hydrogen bond is the attractive force between the hydrogen attached electronegative atom </em>
Explanation:
-- Bathroom tiles are usually cool, so water condenses on them
when you take a hot bath or shower in the room.
-- The natural result is that a smooth tile would become slippery,
exactly when you're walking around with wet feet and nothing on them ...
a dangerous situation.
-- In order to circumvent this safety hazard, the tiles in the bathroom
should be rough, especially on the floor.
