Answer:
Mass = 4152kg
Explanation:
Given
L = 208m
I = 154A
V = 0.245V
Density = 3610 kg/m3
ρ = 4.23 x 10-8Ω·m = resistivity of wire
Resistance R = ρL/ A
R = voltage / current = V/I = 0.245/154 = 1.59×10-³ohms
1.59×10-³ = 4.23 x 10-⁸×208/A
Rearranging,
A = 4.23 x 10-⁸×208/1.59×10-³
A = 5.53×10-³m²
Mass = density × volume
Volume = L×A = 208×5.53×10-³m³= 1.15m³
Mass = 3610×1.15 = 4152kg
The surface area of a cube is:
S = 6l², making l the subject:
l = √(S/6)
While the volume is:
V = l³
If we substitute l to get:
V = (√(S/6))³
√(S/6) = ³√V
S/6 = (³√V)²
S = 6(³√V)² ⇒ 6V^(2/3)
Answer:
1. The image of the person is 1.41 m, virtual and formed at the back of the surface of the globe.
2. The person's image is 3.38 m tall.
Explanation:
From the given question, object distance, u = 0.75 m, object height = 1.8 m, radius of curvature of the reflecting globe, r = 8 cm = 0.08 m.
f =
=
= 0.04 m
1. The image distance, v, can be determined by applying mirror formula:
=
+ 
=
+ 
-
= 
= 
= - 
⇒ v = -
= - 1.41 m
The image of the person is 1.41 m, virtual and formed at the back of the surface of the globe.
2.
= 
= 
v = 
= 3.384
v = 3.38 m
The person's image is 3.38 m tall.
Answer:
f1 = 12.90 Hz
Explanation:
To calculate the first harmonic frequency you use the following formula for n = 1:

( 1 )
It is necessary that the unist are in meters, then you have:
L: length of the string = 60cm = 0.6m
M: mass of the string = 0.05kg
T: tension on the string = 20 N
you replace the values of L, M and T in the expression (1) for getting f1:

Hence, the first harmonic has a frequency of 12.90 Hz
The force on a charged particle in a magnetic field is given by
the speed of the charged particle = 10842 m/s.
Explanation:
F= q V B sinθ
F=force=3.5 x 10⁻²N
q= charge= 8.4 x 10⁻⁴ C
B= magnetic field= 6.7 x 10⁻³ T
θ=35⁰
Thus the velocity is given by V=
V=(3.5 x 10⁻²)/[(8.4 x 10⁻⁴)(6.7 x 10⁻³)(sin35)]
V=10842 m/s