With arms outstretched,
Moment of inertia is I = 5.0 kg-m².
Rotational speed is ω = (3 rev/s)*(2π rad/rev) = 6π rad/s
The torque required is
T = Iω = (5.0 kg-m²)*(6π rad/s) = 30π
Assume that the same torque drives the rotational motion at a moment of inertia of 2.0 kg-m².
If u = new rotational speed (rad/s), then
T = 2u = 30π
u = 15π rad/s
= (15π rad/s)*(1 rev/2π rad)
= 7.5 rev/s
Answer: 7.5 revolutions per second.
Answer:
The ratio of T2 to T1 is 1.0
Explanation:
The gravitational force exerted on each sphere by the sun is inversely proporational to the square of the distance between the sun and each of the spheres.
Provided that the two spheres have the same radius r, the pressure of solar radiation too, is inversely proportional to the square of the distance of each sphere from the sun.
Let F₁ and F₂ = gravitational force of the sun on the first and second sphere respectively
P₁ and P₂ = Pressure of solar radiation on the first and second sphere respectively
M = mass of the Sun
m = mass of the spheres, equal masses.
For the first sphere that is distance R from the sun.
F₁ = (GmM/R²)
P₁ = (k/R²)
T₁ = (F₁/P₁) = (GmM/k)
For the second sphere that is at a distance 2R from the sun
F₂ = [GmM/(2R)²] = (GmM/4R²)
P₂ = [k/(2R)²] = (k/4R²)
T₂ = (F₂/P₂) = (GmM/k)
(T₁/T₂) = (GmM/k) ÷ (GmM/k) = 1.0
Hope this Helps!!!
Answer:
Work done to pull the piano upwards is 401250 J
Explanation:
Work is done against the gravity to pull the piano upwards
So here we can say that work done is
here we know that
also we know that
H = 75 m
now we have
Answer:
659.01W
Explanation:
The cab has a mass of 1250 kg, the weight of the cab represented by Wc will be
Wc = mass of the cab × acceleration due to gravity in m/s²
Wc = 1250 × 9.81 = 12262.5 N
but the counter weight of the elevator represented by We = mass × acceleration due to gravity = 995 × 9.81 = 9760.95 N
Net weight = weight of the cab - counter weight of the elevator = Wc - We = 12262.5 - 9760.95 = 2501.55 N
the motor of the elevator will have to provide this in form of work
work done by the elevator to lift the cab to height of 49 m = net weight × distance (height) = 2501.55 × 49m
power provided by the motor of the elevator = workdone by the motor / time in seconds
Power = (2501.55 × 49) ÷ ( 3.1 × 60 seconds) = 659.01 W
