Mechanics | Relativity Answers

A steel cylinder of 250mm outside and 100mm inside is set in rotation about it's axis. If the cylinder is 900mm long of density 7800kg/m^3. Calculate the moment of inertia of the cylinder about it's polar axis.

A helicopter flies with an airspeed of 42.5 m/s [W]. If the wind is traveling with a velocity of 25.0 m/s [E30°S] relative to the ground then determine the velocity of the helicopter relative to the ground.

Use the data from the question to determine the velocity components for the helicopter’s speed relative to the air and the wind’s speed relative to the ground.
Use your velocity components from part (a) and determine the resultant velocity for each component. (In other words, determine the resultant horizontal component for the helicopter’s ground speed and the resultant vertical component for the helicopter’s ground speed).
Using your data, determine the resultant velocity of the helicopter relative to the ground.

A uniform ladder AB of weight 180N and length 8m, rest in equilibrium with its foot on a rough horizontal ground and its upper end against a rough vertical wall. The ladder makes an angle of 60 degrees with the horizontal ground. The coefficient of friction between the ladder and the wall is 1/4 and that between the ladder and the ground is 1/2. Find the normal reactions at A and B

Answer this question in 30 minutes because I need urgent I have submit my assignment today after 3 hours

Question:
If a twin having age 20 years and one of them went to the space-craft and other
one stayed at earth surface. After ten years what will happen to them with their
age? Explain.
Thanks

The equation y=8Sin(4x–8t) where y is in millimetres,x is in metres and t
is in seconds represent a wave motion.Determine the:
(i) Wavelength
(ii) Frequency
(iii) Period and
(iv) Speed of the wave

What could be reason why a pendulum clock was accurate in lower ground but needed to be adjusted when moved to higher ground

When the roller derby car reaches the bottom of the hill, how fast is it traveling (point C)? (Using g= 10m/s/s and creat am LOL to help solve the problem)

What is the difference between radial and tangential acceleration

2. (a) A particle P moves along the x-axis with constant acceleration a in the positive x-direction. Initially
P is at the origin and is moving with velocity u in the positive x-direction. Show that the velocity v
and displacement x of P at time t are given by
v = u + at, x = ut +
1
2
at2
,
and deduce that
v
2 = u
2 + 2ax.
(b) The trajectory of a charged particle moving in a magnetic field is given by
r = b cos (Ωt)i + b sin (Ωt)j + ctk,
where b, Ω and c are positive constants. Show that the particle moves with constant speed and find the
magnitude of its acceleration.

A projectile shot at an angle of 60° above the horizontal strikes a building 25m away at a point 16m above the point of projection. Find the magnitude and direction of the velocity of the projectile as it strikes the building