C kinetic energy bc it consists of the total kinetic energy of all its atoms and molecules. It is a form of energy related to heat and temperature
Answer:
potential enrgy U = m g L sin θ
speed V = √(2g L sin θ)
Explanation:
The expression for the gravitational potential energy of a body is
U = mg Y - mg Yo
Where Y give us a constant initial energy from which the differences are measured, for general simplicity it is selected as zero, Yo= 0
What we find an expression for height, let's use trigonometry
sin θ= Y / L
Y = l sin θ
We substitute in the power energy equation
U = m g L sin θ
2. The mechanical energy of the system is conserved, so we will write the mechanical energy at two points the highest and the lowest
Highest Em = U
Lower Em = K
U = K
m g L sin θ = ½ m v²
V = √(2g L sin θ)
Answer:
a) d = 7.62 10⁻⁶ m, b) l = 3.25 10⁴ m
Explanation:
Resistance is expressed by the formula
R = ρ l / A (1)
density is defined by
density = m / V
the volume of a wire is the cross section by the length
V = A l
we substitute
density = m / A l
A = m / density l
we substitute in 1
R = ρ l density l / m
R =ρ density l² / m
l = √ (R m /ρ density)
let's calculate the cable length
l = √(11.7 13.5 10⁻³ / (1.68 10⁻⁸ 8.9 10³))
l = √(10.56 10⁸)
l = 3.25 10⁴ m
now we can find the cable diameter with the density equation
A = m / density l
A = 13.5 10⁻³ / (8.9 10³ 3.25 10⁴)
A = 4,557 10⁻¹¹ m²
the area of the circle is
A = π r² = π d² / 4
d = √ (4A /π)
d = √ (4 4,557 10⁻¹¹/π)
d = 7.62 10⁻⁶ m
C is the answer! hope it helps
