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3 years ago

A boy drops a penny down a well. The penny falls for 8 s before splashing into the water. How deep is the well ?

Physics

1 answer:

jenyasd209 [6]3 years ago

5 0

Answer:

IDK

Explanation:

IM sorry ppl i need to answer 5 questions for a task:) so dont mind me lol

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The left face of a biconvex lens has a radius of curvature of magnitude 11.7 cm, and the right face has a radius of curvature of

SIZIF [17.4K]

Answer:

Explanation:

R1 = + 11.7 cm

R2 = - 18.7 cm

n = 1.52

(a) Use lens maker formula

$\frac{1}{f}=\left ( n-1 \right )\left ( \frac{1}{R_{1}}-\frac{1}{R_{2}} \right )$

$\frac{1}{f}=\left ( 1.52-1 \right )\left ( \frac{1}{11.7}}+\frac{1}{18.7} \right )$

$\frac{1}{f}=\frac{0.52\times 30.4}{218.79}$

f = 13.84 cm

(b)

R1 = + 18.7 cm

R2 = - 11.7 cm

n = 1.52

(a) Use lens maker formula

$\frac{1}{f}=\left ( n-1 \right )\left ( \frac{1}{R_{1}}-\frac{1}{R_{2}} \right )$

$\frac{1}{f}=\left ( 1.52-1 \right )\left ( \frac{1}{18.7}}+\frac{1}{11.7} \right )$

$\frac{1}{f}=\frac{0.52\times 30.4}{218.79}$

f = 13.84 cm

5 0

3 years ago

A visitor to a lighthouse wishes to determine the height of the tower. She ties a spool of thread to a small rock to make a simp

masha68 [24]

To solve this problem we must rely on the equations of the simple harmonic movement that define the period as a function of length and gravity as

$T = 2\pi \sqrt{\frac{l}{g}}$

Where

l = Length

g = Gravity

Re-arrange to find L,

$L = g (\frac{T}{2\pi})^2$

Our values are given as

$g = 9.81m/s$

$T = 10.1s$

Replacing,

$L = g (\frac{T}{2\pi})^2$

$L = (9.81) (\frac{10.1}{2\pi})^2$

$L = 25.348m$

Therefore the height would be 25.348m

5 0

3 years ago

If a car takes a banked curve at less than the ideal speed, friction is needed to keep it from sliding toward the inside of the

PolarNik [594]

Answer:

a. v₁ = 16.2 m/s

b. μ = 0.251

Explanation:

Given:

θ = 15 ° , r = 100 m , v₂ = 15.0 km / h

To determine v₁ to take a 100 m radius curve banked at 15 °

tan θ = v₁² / r * g

v₁ = √ r * g * tan θ

v₁ = √ 100 m * 9.8 m/s² * tan 15° = 16.2 m/s

To determine μ friction needed for a frightened

v₂ = 15.0 km / h * 1000 m / 1 km * 1h / 60 minute * 1 minute / 60 seg

v₂ = 4.2 m/s

fk = μ * m * g

a₁ = v₁² / r = 16.2 ² / 100 m = 2.63 m/s²

a₂ = v₂² / r = 4.2 ² / 100 m = 0.18 m/s²

F₁ = m * a₁ , F₂ = m * a₂

fk = F₁ - F₂ ⇒ μ * m * g = m * ( a₁ - a₂)

μ * g = a₁ - a₂ ⇒ μ = a₁ - a₂ / g

μ = [ 2.63 m/s² - 0.18 m/s² ] / (9.8 m/s²)

μ = 0.251

3 0

3 years ago

Carbon-14 is used to determine the time an organism was living. The amount of carbon-14 an organism has is constant with the atm

lutik1710 [3]

Answer:

The age of the organism is approximately 11460 years.

Explanation:

The amount of carbon-14 decays exponentially in time and is defined by the following equation:

$\frac{n(t)}{n_{o}} = e^{-\frac{t}{\tau} }$ (1)

Where:

$n_{o}$ - Initial amount of carbon-14.

$n(t)$ - Current amount of carbon-14.

$t$ - Time, measured in years.

$\tau$ - Time constant, measured in years.

Then, we clear the time within the formula:

$t = -\tau \cdot \ln \frac{n(t)}{n_{o}}$ (2)

In addition, time constant can be calculated by means of half-life of carbon-14 ( $t_{1/2}$ ), measured in years:

$\tau = \frac{t_{1/2}}{\ln 2}$

If we know that $\frac{n(t)}{n_{o}} = 0.25$ and $t_{1/2} = 5730\,yr$ , then the age of the organism is:

$\tau = \frac{5730\,yr}{\ln 2}$

$\tau \approx 8266.643\,yr$

$t = -(8266.643\,yr)\cdot \ln 0.25$

$t \approx 11460.001\,yr$

The age of the organism is approximately 11460 years.

8 0

3 years ago

Read 2 more answers

Explain what voltage,current, resistance are and how they relate to Ohms law. Then give examples

SOVA2 [1]

Voltage is the difference in charge between two points.
Current is the rate the charge flows
Resistance is the tendency a material has to resist the flow of charge (current)
Combining voltage resistance and current Ohm developed the formula
V (Voltage)= I (Current) x R (Resistance)

3 0

3 years ago