Answer: 6.36
Explanation:
Given
Radius of grindstone, r = 4 m
Initial angular speed of grindstone, w(i) = 8 rad/s
Final angular speed of the grindstone, w(f) = 12 rad/s
Time used, t = 4 s
Angular acceleration of the grinder,
α = Δw / t
α = w(f) - w(i) / t
α = (12 - 8) / 4
α = 4/4 = 1 rad/s²
Number of complete revolution in 4s =
Δθ = w(i).t + 1/2.α.t²
Δθ = 8 * 4 + 1/2 * 1 * 4²
Δθ = 32 + 1/2 * 16
Δθ = 32 + 8
Δθ = 40 rad/s
40 rad/s = 40/2π rpm = 6.36 rpm
Therefore, the grindstone does 6.36 revolutions during the 4 s interval
We will use this equation:
s = 1/2*a*t^2 + v0*t + s0
where:
s = space traveled
a = acceleration
t = time
v0 = initial speed
s0 = initial space
In this case::
v0 = 0
s0 = 0
So our equation will look like that now:
s = 1/2 * a * t^2
let's calculate the acceleration first of all:
a = (vf - vi) / t
where vf is the final speed and vi is the initial speed. t is the time.
a = (25m/s) / 10s = 2.5 m/s^2
Now we can calculate the space:
s = 1/2 * (2.5 m/s^2) * (10s)^2 = 125m
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Hope it was helpful! Have a great day.
The last option in Puerto Rico where it’s sunny and 88°
The distance the object travels
Answer:
Waxing crescent to Waxing gibbous
Explanation:
As the Moon goes around Earth and Earth goes around the Sun, the Moon shows us different phases throughout this journey. Also because of peculiar revolution period around the Earth the rise and set time of Moon changes daily. New Moon rises with the Sun rise and sets with Sun set. Waxing half rises in the mid of the day and sets at midnight. Full Moon rises after sunset and sets at sunrise.
The suitable phases will be from waxing crescent to waxing gibbous. The phase of the Moon, 3 days before the full Moon can be selected as the Moon will set by around 2.5 hours before the Sun rise.
