Answer:
(a) 2.88×10⁻² W/m²
(b) 8.36×10⁻³ W/m²
Explanation:
The intensity of sound from an isotropic point source, with distance L is given as
I = P/(4πL²) .................................... Equation 1
Where I = intensity of sound, P = Power from the source, L = length, π = pie.
(a)
1.4 m from the source.
I = P/(4πL²)
Given: P = 0.71 W, L = 1.4 m, π = 3.14.
Substitute into equation 1
I = 0.71/(4×3.14×1.4²)
I = 0.71/24.6176
I = 0.0288 W/m².
I = 2.88×10⁻² W/m²
(b) 2.6 m from the source.
Given: P = 0.71 W, L = 2.6 m, π = 3.14
Substitute into equation 1
I = 0.71/(4×3.14×2.6²)
I = 0.71/84.9056
I = 0.00836 W/m²
I = 8.36×10⁻³ W/m²
Power is calculated as work per unit time, and work in turn is calculated as force multiplied by distance. In this case, the force required is equivalent to the weight of the barbell multiplied by acceleration due to gravity.
P = W/t = Fd/t = mgd/t = (200 kg)(9.81 m/s^2)(2 m)/2.2 s = 1783.64 Watts.
Answer:
<em>1.228 x </em>
<em> mm </em>
<em></em>
Explanation:
diameter of aluminium bar D = 40 mm
diameter of hole d = 30 mm
compressive Load F = 180 kN = 180 x
N
modulus of elasticity E = 85 GN/m^2 = 85 x
Pa
length of bar L = 600 mm
length of hole = 100 mm
true length of bar = 600 - 100 = 500 mm
area of the bar A =
=
= 1256.8 mm^2
area of hole a =
=
= 549.85 mm^2
Total contraction of the bar =
total contraction =
==>
= <em>1.228 x </em>
<em> mm </em>
Answer;
The above statement is true.
-A photograph is taken by letting light fall on a light-sensitive medium, which then records the image onto that medium.
Explanation;
-A photograph is created when light is allowed to fall on a light-sensitive medium. The pattern of light creates an image that is recorded by the photographic device. How light or dark a photograph is depends on how much light was allowed to fall on the light-sensitive medium.
-A camera is a light-tight box that contains a light-sensitive material or device and a way of letting in a desired amount of light at particular times to create an image on the light-sensitive material.
Answer:
C. less than 950 N.
Explanation:
Given that
Force in north direction F₁ = 500 N
Force in the northwest F₂ = 450 N
Lets take resultant force R
The angle between force = θ
θ = 45°
The resultant force R


R= 877.89 N
Therefore resultant force is less than 950 N.
C. less than 950 N
Note- When these two force will act in the same direction then the resultant force will be 950 N.