All categories

3 years ago

Physics/Math

Physics

1 answer:

Korolek [52]3 years ago

6 0

Answer:

f = pl / (l + p)

Explanation:

1/f = 1/p + 1/l

Find the common denominator of the right hand side.

1/f = l/(pl) + p/(pl)

Add:

1/f = (l + p) / (pl)

Take the inverse of both sides:

f = pl / (l + p)

You might be interested in

Consider a situation of simple harmonic motion in which the distance between the endpoints is 2.39 m and exactly 8 cycles are co

aivan3 [116]

Answer:

1.195 m

2.8375 s

2.21433 rad/s

Explanation:

d = Distance = 2.39 m

N = Number of cycles = 8

t = Time to complete 8 cycles = 22.7 s

Radius would be equal to the distance divided by 2

$r=\frac{d}{2}\\\Rightarrow r=\frac{2.39}{2}\\\Rightarrow r=1.195\ m$

The radius is 1.195 m

Time period would be given by

$T=\frac{t}{N}\\\Rightarrow T=\frac{22.7}{8}\\\Rightarrow T=2.8375\ s$

Time period of the motion is 2.8375 s

Angular speed is given by

$\omega=\frac{2\pi}{T}\\\Rightarrow \omega=\frac{2\pi}{2.8375}\\\Rightarrow \omega=2.21433\ rad/s$

The angular speed of the motion is 2.21433 rad/s

4 0

3 years ago

A bungee jumper with mass 65.0 kg jumps from a high bridge. After reaching his lowest point, he oscillates up and down, hitting

ololo11 [35]

Explanation:

It is given that,

Mass of a bungee jumper is 65 kg

The time period of the oscillation is 38 s, hitting a low point eight more times.It means its time period is

$T=\dfrac{38}{8}\\\\T=4.75\ s$

After many oscillations, he finally comes to rest 25.0 m below the level of the bridge.

For an oscillating object, the time period is given by :

$T=2\pi \sqrt{\dfrac{m}{k}}$

k = spring stiffness constant

So,

$k=\dfrac{4\pi ^2m}{T^2}\\\\k=\dfrac{4\pi ^2\times 65}{(4.75)^2}\\\\k=113.43\ N/m$

When the cord is in air,

mg=kx

x = the extension in the cord

$x=\dfrac{mg}{k}\\\\x=\dfrac{65\times 9.8}{113.6}\\\\x=5.6\ m$

So, the unstretched length of the bungee cord is equal to 25 m - 5.6 m = 19.4 m

5 0

3 years ago

Why are there only two elements in the first period of the periodic table?(1 point)

tester [92]

Answer:

because each row increases in atomic mass by a specific number, so anything over five is in the second row.

8 0

3 years ago

Sheila weighs 60 kg and is riding a bike. Her momentum on the bike is 340 kg • m/s. The bike hits a rock, which stops it complet

Vikki [24]

Answer:

v₂ = 5.7 m/s

Explanation:

We will apply the law of conservation of momentum here:

$Total\ Initial\ Momentum = m_{1}v_{1} + m_{2}v_{2}\\$

where,

Total Initial Momentum = 340 kg.m/s

m₁ = mass of bike

v₁ = final speed of bike = 0 m/s

m₂ = mass of Sheila = 60 kg

v₂ = final speed of Sheila = ?

Therefore,

$340\ kg.m/s = m_{1}(0\ m/s) + (60\ kg)v_{2}\\v_{2} = \frac{340\ kg.m/s}{60\ kg}\\\\$

6 0

3 years ago

A current of 2 A flows through a resistor. The voltage across the resistor is 18 V.

stepan [7]

Answer:

$R=9\ \Omega$

Explanation:

Given that,

Current, I = 2 A

Voltage across the resistor, V = 18 V

We need to find the value of resistance of the resistor. Let the resistance be R. We can find it using Ohm's law i.e.

V = IR

Where

R is the resistance of the resistor

$R=\dfrac{V}{I}\\\\R=\dfrac{18}{2}\\\\R=9\ \Omega$

So, the resistance of the resistor is equal to $9\ \Omega$ .

3 0

3 years ago