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
Answer:
KE=800,000
Explanation:
The formula for kinetic energy is KE=1/2mv^2 or Kinetic Energy= 0.5*mass*velocity^2
so 1000 is the mass and 40 is the velocity
KE=0.5*1000*40^2
KE=0.5*1,000*1,600
KE=800,000 Joules
The answer is D. 32 m.
The simple equation that connects speed (v), time (t), and distance (d) can be expressed as:

⇒

It is given:

t = 10 s
d = ?
So:
For this specific problem, the photons have been localized to
D<span>x = </span>0.027m
uncertainty. I am hoping that this answer has satisfied your
query about and it will be able to help you, and if you’d like, feel free to
ask another question.
Dropping a bouncy ball and stretching a rubber ban.