Answer:
1.97 m/s
Explanation:
The initial angular velocity of the blades is:
The final angular velocity is
(since the blades come to a stop)
and the time taken is
t = 30 s
So, the angular acceleration of the blades is
Now we can find the angular velocity of a blade after a time t=10 s:
The distance of the tip of a blade from the centre is equal to half the diameter, so
so, the speed of the tip of a blade is
KE= 0.5(m)(v^2)
KE= 250,000 J
- 1000 mph is the speed of an airplane,
- 100 mph is the speed of a sport car.
- 1 mph is the walking speed.
Answer: The best estimate for the speed of a boy going fast on the skateboard is B ) 1 mph.
Disagree.
Fluoresce objects will only glow when put under actual Ultraviolet light. This is due to the molecules becoming excited by the ultraviolet radiation.
Microwaves give micro-waves that are present in another spectrum of wave length and will not be able to fluoresce the molecules. If it’s not “ultra violet “.... it’s not going to glow.