<span>P = energy/t = 0.0025/1E-8 = 250000 W
I(ave) = P/A = 250000/(pi*0.425E-3^2) = 4.4056732E11 W/m^2
I(peak) = 2I(ave) = 8.8113463E11 W/m^2
Electric field E = sqrt(I(peak)*Z0) = 1.8219499E7 V/m, where
free-space impedance Z0 = sqrt(µ0/e0) = 376.73031 ohms</span>

7 0

3 years ago

A holiday ornament in the shape of a hollow sphere with mass 0.015 kg and radius 0.055 m is hung from a tree limb by a small loo

s344n2d4d5 [400]

Answer: 0.61 s

Explanation:

Given

Mass of object, m = 0.015 kg

Radius of object, r = 0.055 m

Acceleration of object, g = 9.8 m/s²

In a pendulum,

T = 2π * √[I /(mgd)]

The moment of Inertia, I of a hollow sphere is given by

I(sphere) = 2/3MR² + MR²

I(sphere) = 5/3MR²

Also, d = R

Substituting these into the first equation, we have

T = 2π * √[(5/3MR²) / (mgr)]

T = 2π * √[(5/3r) / (g)]

T = 2 * 3.142 * √(5/3 * 0.055) / (9.8)]

T = 6.284 * √(0.092/9.8)

T = 6.284 * √0.00939

T = 6.284 * 0.097

T = 0.6095 s

To 2 significant figures,

The period is 0.61 s

7 0

3 years ago