Answer:9.75 m/s
Explanation:
Given
Length of ladder 
Foot the ladder is moving away with speed of 
From diagram
------1
at 


Now differentiating equation 1 w.r.t time




negative indicates distance is decreasing with time
Answer:
Option B
It converts light into electric current
Explanation:
A photometer is a device used to measure illuminance
Its principle of operation hinges on the conversion of light into electric current, using photoresistor or any other light sensitive device such as a photodiode. This is so that it can be read off easily by any other device.
A Photoresistor is a device that changes the flow of current through it when it is exposed to light rays. A photometer works by irradiating a photo resistor, which then converts the light rays incident on it to electric current.
Okay, I don't know if this question is supposed to be a trick question or not. The weight of the apple does not change as the plane travels up the atmosphere, but the MASS changes. Weight doesn't change no matter what environment you're in, but the mass changes in different environments. In this case, the weight is constant but the mass is decreasing as you go higher up.
Answer:
(a) t = 5.66 s
(b) t = 8 s
Explanation:
(a)
Here we will use 2nd equation of motion for angular motion:
θ = ωi t + (1/2)∝t²
where,
θ = Angular Displacement = (3.7 rev)(2π rad/1 rev) = 23.25 rad
ωi = initial angular speed = 0 rad/s
t = time = ?
∝ = angular acceleration = 1.45 rad/s²
Therefore,
23.25 rad = (0 rad/s)(t) + (1/2)(1.45 rad/s²)t²
t² = (23.25 rad)(2)/(1.45 rad/s²)
t = √(32.06 s²)
<u>t = 5.66 s</u>
<u></u>
(b)For next 3.7 rev
θ = ωi t + (1/2)∝t²
where,
θ = Angular Displacement = (3.7 rev + 3.7 rev)(2π rad/1 rev) = 46.5 rad
ωi = initial angular speed = 0 rad/s
t = time = ?
∝ = angular acceleration = 1.45 rad/s²
Therefore,
46.5 rad = (0 rad/s)(t) + (1/2)(1.45 rad/s²)t²
t² = (46.5 rad)(2)/(1.45 rad/s²)
t = √(64.13 s²)
<u>t = 8 s</u>
<span>Buddy, remember one formula.. speed=distance/time
your all problems will be solved.
in this case the answer is 5 km per hr</span>