Answer:
a)
, b) 
Explanation:
a) The distance between the center and one of the foci is:



The shortest distance is:



b) The longest distance is:



F = m · a
In order to accelerate 82 kg upward at the rate of 3.2 m/s², a NET upward force of (82kg · 3.2m/s²) = 262.4 Newtons is required.
But if the object is on or near the surface of the Earth, then there's a downward force of (82kg · 9.8m/s²) = 803.6 N already acting on it because of gravity.
So you need to apply (803.6N + 262.4N) = <em>1,066 Newtons UPward</em>, in order to cancel its own weight and accelerate it upward at that rate.
Answer:
A chain reaction will be sustained in a sub-critical mass.
Explanation:
Hope this helps!
If not, I am sorry.
The answer is C. Convection.
Radiation is the transfer of energy through electromagnetic waves. Conduction, on the other hand, is energy transfer through solid material. Condensation occurs when warm gas makes contact with a cold surface or environment, which causes a change in state from gas to liquid. These definitions rule out choices A, B, and D.
Convection is movement of particles in fluid or gas. As liquid/gas heats up, it becomes less dense and rises, moving away from the heat source. When it rises, it eventually cools down and sinks again. It is warmed up again and the cycle continues. This is why there is a circular motion when convection occurs.
Answer:
C) True. At maximum displacement, its instantaneous velocity is zero.
Explanation:
The simple harmonic movement is given by
x = A cos wt
Speed
v = - A w sin wt
At the point of maximum displacement x = A
A = A cos wt
cos wt = 1
wt = 0
We replace the speed
v = -Aw sin 0 = A w
Speed is maximum
Let's review the claims
A) False. Speed is zero
B) False. It can be determined
C) True. Agree with our result
D) False. When one is maximum the other is minimum