Answer:
The doorbell transforms electrical energy into sound.
Explanation:
The doorbell MAY turn electrical energy into motion of a striker which then impacts a resonator creating sound. However all door bells do not have solenoids. Some are electronic playing recordings when activated.
All doorbells do produce sound, though.
The distance between city a and city b is 833.345 miles.
We know that
1°=60'
The distance of city a from the initial ray is calculated as
x_a=3960*tan45.46°=4024.101 miles
The distance of city b from the initial ray is calculated as
x_b=3960*tan 38.86°=3190.75 miles
Now the distance between city a and b is equal to
4024.101-3190.75=833.345 miles
This is the vertical distance between the cities.
Answer:
576 joules
Explanation:
From the question we are given the following:
weight = 810 N
radius (r) = 1.6 m
horizontal force (F) = 55 N
time (t) = 4 s
acceleration due to gravity (g) = 9.8 m/s^{2}
K.E = 0.5 x MI x ω^{2}
where MI is the moment of inertia and ω is the angular velocity
MI = 0.5 x m x r^2
mass = weight ÷ g = 810 ÷ 9.8 = 82.65 kg
MI = 0.5 x 82.65 x 1.6^{2}
MI = 105.8 kg.m^{2}
angular velocity (ω) = a x t
angular acceleration (a) = torque ÷ MI
where torque = F x r = 55 x 1.6 = 88 N.m
a= 88 ÷ 105.8 = 0.83 rad /s^{2}
therefore
angular velocity (ω) = a x t = 0.83 x 4 = 3.33 rad/s
K.E = 0.5 x MI x ω^{2}
K.E = 0.5 x 105.8 x 3.33^{2} = 576 joules
the force applied when using a simple machine is called the effort force
