The angular acceleration of the blade when it's switched off is (-6800 rev/min) divided by (2.8 sec) = -2,428.6 rev/(min-sec) = -40.5 rev/sec^2 .
Answer:
Speed of the airplane 10.0 s later = 12.2 m/s
Explanation:
Mass of Boeing 777 aircraft = 300,000 kg
Braking force = 445,000 N
Deceleration
Initial velocity, u = 27 m/s
Time , t = 10 s
We have equation of motion, v =u +at
v = 27 + (-1.48) x 10 = 27 - 14.8 = 12.2 m/s
Speed of the airplane 10.0 s later = 12.2 m/s
"Gamma rays" is the name that we call the shortest of all electromagnetic waves. They're shorter than radio waves, microwaves, infrared waves, heat waves, visible light waves, ultraviolet waves, and X-rays. They extend all the way down to waves that are as short as the distance across an atom.
Being so short, they carry lots of energy. They can penetrate many materials, and they can damage living cells and DNA. They're dangerous.
The sun puts out a lot of gamma radiation. The atmosphere (air) filters out a lot of it, otherwise there couldn't even be any life on Earth.
As soon as astronauts fly out of the atmosphere, they need a lot of shielding from gamma rays.
You know the precautions we take when we're around X-rays. The same precautions apply around gamma rays, only a lot more so.
It's only in the past several years that we've learned how to MAKE gamma rays without blowing things up. Also, how to control them, and how to use them for medical and industrial applications.
Answer:
, it will sink
Explanation:
The density of an object is given by
where
m is the mass of the object
V is its volume
For the body in the problem, we have
m = 4 kg = 4000 g
Therefore, its density is
And the object will sink in water, because its density is larger than that of water, which is 
. (an object sinks when its density is larger than that of water, otherwise it floats).
The basketball would be sun then baseball earth and finally golf ball moon.
