Answer:
2×10⁻⁷ Ωm
Explanation:
From the question,
R = 4ρL/πd².................... Equation 1
Where R = Resistance of the wire, ρ = resistivity of the wire, L = length of the wire, d = diameter of the wire.
Therefore,
ρ = Rπd²/4L............. Equation 2
Given: R = 1 ohm, ρ = 1×10⁻⁷Ωm
1×10⁻⁷ = πd²/4L.................... Equation 3
If the length and the diameter are doubled, and the resistance remaining constant
ρ' = π(2d)²/4(2L)
Where ρ' = new resistivity
ρ' = 4πd²/8L
ρ' = 2πd²/4L = 2ρ
ρ' = 2(1×10⁻⁷)
ρ' = 2×10⁻⁷ Ωm
Answer:
(B) Reduction in the population of fish in the pond that eat plants
Answer:
d =
m
V
m = d×V
V =
m
d
DENSITY
Density is defined as mass per unit volume.
d =
m
V
Example:
A brick of salt measuring 10.0 cm x 10.0 cm x 2.00 cm has a mass of 433 g. What is its density?
Step 1: Calculate the volume
V = lwh = 10.0 cm × 10.0 cm × 2.00 cm = 200 cm³
Step 2: Calculate the density
d =
m
V
=
433
g
200
c
m
³
= 2.16 g/cm³
MASS
d =
m
V
We can rearrange this to get the expression for the mass.
m = d×V
Example:
If 500 mL of a liquid has a density of 1.11 g/mL, what is its mass?
m = d×V = 500 mL ×
1.11
g
1
m
L
= 555 g
VOLUME
d =
m
V
We can rearrange this to get the expression for the volume.
V =
m
d
Example:
What is the volume of a bar of gold that has a mass of 14.83 kg. The density of gold is 19.32 g/cm³.
Step 1: Convert kilograms to grams.
14.83 kg ×
1000
g
1
k
g
= 14 830 g
Step 2: Calculate the volume.
V =
m
d
= 14 830 g ×
1
c
m
³
19.32
g
= 767.6 cm³
Explanation: got it from a site
Answer:
(a) vo = 24.98m/s
(b) t = 5.09 s
Explanation:
(a) In order to calculate the the initial speed of the ball, you use the following formula:
(1)
y: vertical position of the ball = 2.44m
yo: initial vertical position = 0m
vo: initial speed of the ball = ?
g: gravitational acceleration = 9.8m/s²
t: time on which the ball is at 2.44m above the ground = 5.00s
You solve the equation (1) for vo and replace the values of the other parameters:
The initial speed of the ball is 24.98m/s
(b) To find the time the ball takes to arrive to the ground you use the equation (1) for y = 0m (ground) and solve for t:
The time that the ball takes to arrive to the ground is 5.09s
Answer: 500 volts
Explanation:
Voltage of circuit V = ?
Resistance R = 10Ω ( ohms is represented by the symbol Ω)
Current, I = 50Amp
Now recall that:
Voltage = current x resistance
i.e V = I x R
V = 50Amps x 10Ω
V = 500 volts
Thus, there is 500 volts of voltage in the circuit