Answer:

Explanation:
When she moved a distance of 1 m from mid point she observe first destructive interference due to two speakers
so we can say that path difference of sound due to two speakers will be equal to half of the wavelength
so path difference is given as

so it will be


now we know that


now frequency of sound is given as



Answer:
400cm^2
Explanation:
sides are 20cm long Area for a square is a squared
since all the lides are of equal length you can just choose one side.
20squared is 400
20 x 20 = 400cm squared
Hope this helps :)
Work = force x distance
F= 2.5
D= 3
Work = 2.5 x 3 =7.5
Work = 7.5 J
J=Jules (Jules is the unit uses to calculate work)
The 'formulas' to use are just the definitions of 'power' and 'work':
Power = (work done) / (time to do the work)
and
Work = (force) x (distance) .
Combine these into one. Take the definition of 'Work', and write it in place of 'work' in the definition of power.
Power = (force x distance) / (time)
From the sheet, we know the power, the distance, and the time. So we can use this one formula to find the force.
Power = (force x distance) / (time)
Multiply each side by (time): (Power) x (time) = (force) x (distance)
Divide each side by (distance): Force = (power x time) / (distance).
Look how neat, clean, and simple that is !
Force = (13.3 watts) x (3 seconds) / (4 meters)
Force = (13.3 x 3 / 4) (watt-seconds / meter)
Force = 39.9/4 (joules/meter)
<em>Force = 9.975 Newtons</em>
Is that awesome or what !
Answer:
x = 0.6034 m
Explanation:
Given
L = 5 m
Wplank = 225 N
Wman = 522 N
d = 1.1 m
x = ?
We have to take sum of torques about the right support point. If the board is just about to tip, the normal force from the left support will be going to zero. So the only torques come from the weight of the plank and the weight of the man.
∑τ = 0 ⇒ τ₁ + τ₂ = 0
Torque come from the weight of the plank = τ₁
Torque come from the weight of the man = τ₂
⇒ τ₁ = + (5 - 1.1)*(225/5)*((5 - 1.1)/2) - (1.1)*(225/5)*((1.1)/2) = 315 N-m (counterclockwise)
⇒ τ₂ = Wman*x = 522 N*x (clockwise)
then
τ₁ + τ₂ = (315 N-m) + (- 522 N*x) = 0
⇒ x = 0.6034 m