Answer:
Lifting force, F = 21240 N
Explanation:
It is given that,
Mass of the helicopter, m = 1800 kg
It rises with an upward acceleration of 2 m/s². We need to find the lifting force supplied by its rotating blades. It is given by :
F = mg + ma
Where
mg is its weight
and "ma" is an additional acceleration when it is moving upwards.
So, 
F = 21240 N
So, the lifting force supplied by its rotating blades is 21240 N. Hence, this is the required solution.
1.) The object's Velocity
Faster it goes, more kinetic energy it has
Question
What is the length of the pipe?
Answer:
(a) 0.52m
(b) f2=640 Hz and f3=960 Hz
(c) 352.9 Hz
Explanation:
For an open pipe, the velocity is given by
Making L the subject then
Where f is the frequency, L is the length, n is harmonic number, v is velocity
Substituting 1 for n, 320 Hz for f and 331 m/s for v then
(b)
The next two harmonics is given by
f2=2fi
f3=3fi
f2=3*320=640 Hz
f3=3*320=960 Hz
Alternatively, 
and 
(c)
When v=367 m/s then
Answer:
Depends on what pole it is.
Explanation:
If the poles of the cars and magnets are the same they will repel, if different, attracts.
Answer: coefficient of static friction
= 0.31
Explanation: Since they negotiate the curve without skidding, the frictional force (F1) equals the centripetal force (F2).
F1= uN
F2 = M*(v²/r)
M is the combined mass 450kg
V is the velocity 18m/s
r is the radius 106m
N is the normal reaction 4410N
u is the coefficient of static friction
Making u subject of the formula we have that,
u = {450*(18²/106)} /4410
=1375.47/4410
=0.31
NOTE: coefficient of friction is dimensionless. It as no Unit.
