Should i make my pet shark bark like a dog woof woof

During each cycle of operation a refrigerator absorbs 56 cal from the freezer compartment and expels 81 cal tothe room. If one c

Alexandra [31]

Answer:

138.18 minutes

Explanation:

$L_v$ = Latent heat of water at 0°C = 80 cal/g

m = Mass of water = 570 g

Heat removed for freezing

$Q=mL_v\\\Rightarrow Q=570\times 80\\\Rightarrow Q=45600\ cal$

Let N be the number of cycles and each cycle removes 56 cal from the freezer.

So,

$55\times N=45600\\\Rightarrow N=\frac{45600}{55}$

Each cycle takes 10 seconds so the total time would be

$\frac{45600}{55}\times \frac{10}{60}=138.18\ minutes$

The total time taken to freeze 138.18 minutes

6 0

3 years ago

A 200N force pushes forward on the 20kg truck. The truck pulls two crates connected together by ropes, as shown. The gravitation

devlian [24]

Force on left crate, right crate and truck we need to draw here

First we will write the equation for left crate

$T_{left} = m*a$

$T_{left} = 20*a$

Now similarly for right crate

$T_{right} - T_{left} = 20*a$

now for truck

$F - T_{right} = 20*a$

Now we know that F = 200 N

$200 - T_{right} = 20*a$

now add all three equation

$T_{left} + T_{right} - T_{left} + 200 - T{right} = 20a + 20 a + 20a$

$200 = 60 a$

$a = 10/3 m/s^2$

now we will find all tension using this value of acceleration

$T_{left} = 20 * \frac{10}{3} = \frac{200}{3} N$

$T_{right} - \frac{200}{3} = 20*\frac{10}{3}$

$T_{right} = \frac{400}{3} N$

6 0

3 years ago

The following table lists the work functions of a few commonmetals, measured in electron volts.

steposvetlana [31]

Answer:

Lithium

Explanation:

The equation for the photoelectric effect is

$\frac{hc}{\lambda}= \phi + K_{max}$

where

$\frac{hc}{\lambda}$ is the energy of the incident photon, with

h being the Planck constant

c is the speed of light

$\lambda$ is the wavelength of the photon

$\phi$ is the work function of the metal (the minimum energy needed to extract the photoelectron from the metal)

$K_{max}$ is the maximum kinetic energy of the emitted photoelectrons

In this problem, we have

$\lambda= 190 nm = 1.9\cdot 10^{-7}m$ is the wavelength of the incident photon

$K_{max}=4.0 eV$ is the maximum kinetic energy of the electrons

First of all we can find the energy of the incident photon

$E=\frac{(6.63\cdot 10^{-34} Js)(3\cdot 10^8 m/s)}{1.90\cdot 10^{-7} m}=1.05\cdot 10^{-18} J$

Converting into electronvolts,

$E=\frac{1.05\cdot 10^{-18} J}{1.6\cdot 10^{-19} J/eV}=6.6 eV$

So now we can re-arrange the equation of the photoelectric effect to find the work function of the metal

$\phi = E-K_{max}=6.6 eV - 4.0 eV=2.6 eV$

So the metal is most likely Lithium, which has a work function of 2.5 eV.

3 0

3 years ago

A wave hits a wall as shown. A brick wall with a green arrow pointing to the wall from below and right at a shallow angle. Anoth

bulgar [2K]

Answer:

reflection

Explanation:

5 0

2 years ago

Block A is also connected to a horizontally-mounted spring with a spring constant of 281 J/m2. What is the angular frequency (in

Svetradugi [14.3K]

Answer:

This question is incomplete

Explanation:

This question is incomplete. However, the formula to be used here is

ω = 2π/T

Where ω is the angular frequency (in rad/s)

T is the period - the time taken for Block A to complete one oscillation and return to it's original position.

To solve for this period T, the formula below should be used

T = 2π√m/k

where m is the mass of the object (Block A) and k is the spring constant (281 J/m²)

5 0

3 years ago

Should i make my pet shark bark like a dog woof woof​

Should i make my pet shark bark like a dog woof woof