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scoundrel [369]

3 years ago

9

After dinner, Joanne did not put the leftover casserole away until after watching her favorite television show. What is the long

est time it should be left out at room temperature?

1 answer:

Sever21 [200]3 years ago

7 0

Answer:

At most 2 hours

Explanation:

According to my research of various health departments it is said that cooked food should not be left out in room temperature for more than 2 hours, assuming that room temperature is between 40°F and 140°F. This is because after 2 hours bacteria starts to grow at an increased rate and can have various health effects on the person consuming the food. Therefore food is best wrapped and placed in the refrigerator.

I hope this answered your question. If you have any more questions feel free to ask away at Brainly.

You might be interested in

What is the time constant of a 9.0-nm-thick membrane surrounding a 0.040-mm-diameter spherical cell? Assume the resistivity of t

yawa3891 [41]

Given Information:

Diameter of spherical cell = 0.040 mm

thickness = L = 9 nm

Resistivity = ρ = 3.6×10⁷ Ω⋅m

Dielectric constant = k = 9.0

Required Information:

time constant = τ = ?

Answer:

time constant = 2.87×10⁻³ seconds

Explanation:

The time constant is given by

τ = RC

Where R is the resistance and C is the capacitance.

We know that resistivity of of any material is given by

ρ = RA/L

R = ρL/A

Where area of spherical cell is given by

A = 4πr²

A = 4π(d/2)²

A = 4π(0.040×10⁻³/2)²

A = 5.026×10⁻⁹ m²

The resistance becomes

R = (3.6×10⁷*9×10⁻⁹)/5.026×10⁻⁹

R = 6.45×10⁷ Ω

The capacitance of the cell membrane is given by

C = kεoA/L

Where k = 9 is the dielectric constant and εo = 8.854×10⁻¹² F/m

C = (9*8.854×10⁻¹²*5.026×10⁻⁹)/9×10⁻⁹

C = 44.5 pF

C = 44.5×10⁻¹² F

Therefore, the time constant is

τ = RC

τ = 6.45×10⁷*44.5×10⁻¹²

τ = 2.87×10⁻³ seconds

6 0

3 years ago

An air balloon is moving upward at a constant speed of 3 m/s. Suddenly a passenger realizes that she left her camera on the grou

frosja888 [35]

Answer:t=0.3253 s

Explanation:

Given

speed of balloon is $u=3\ m/s$

speed of camera $u_1=20\ m/s$

Initial separation between camera and balloon is $d_o=5\ m$

Suppose after t sec of throw camera reach balloon then,

distance travel by balloon is

$s=ut$

$s=3\times t$

and distance travel by camera to reach balloon is

$s_1=ut+\frac{1}{2}at^2$

$s_1=20\times t-\frac{1}{2}gt^2$

Now

$\Rightarrow s_1=5+s$

$\Rightarrow 20\times t-\frac{1}{2}gt^2 =5+3t$

$\Rightarrow 5t^2-17t+5=0$

$\Rightarrow t=\dfrac{17\pm \sqrt{17^2-4(5)(5)}}{2\times 5}$

$\Rightarrow t=\dfrac{17\pm 13.747}{10}$

$\Rightarrow t=0.3253\ s\ \text{and}\ t=3.07\ s$

There are two times when camera reaches the same level as balloon and the smaller time is associated with with the first one .

(b)When passenger catches the camera time is $t=0.3253\ s$

velocity is given by

$v=u+at$

$v=20-10\times 0.3253$

$v=16.747\ m/s$

and position of camera is same as of balloon so

Position is $=5+3\times 0.3253$

$=5.975\approx 6\ m$

8 0

3 years ago

A resonance tube can be used to measured the speed of sound in air. A tuning fork is held above the opening of the tube and stru

LenaWriter [7]

Answer:

330.24 Hz

Explanation:

Given:

Frequency, f = 320 Hz

L1 = 25.8 cm

L2 = 78.4 cm

L3 = 131.1 cm

Let the wavelength be λ

Then, L1 which is the length of the column of air is λ/4.

λ/4 = 25.8 cm

λ = 25.8 × 4 = 103.2 cm = 1.032 m

Then, speed of sound in air is:

v = λ f

⇒ v = 1.032 × 320 Hz

⇒ v = 330.24 m/s

7 0

3 years ago

What is the wavelength of microwave of 3 x 10 9 Hz frequency?

jok3333 [9.3K]

The wavelength of a microwave of 3 x 10^9 Hz frequency is 0.1 m.

The wavelength of a microwave of 3 x 10^9 Hz frequency is calculated using the equation λ = c/f, where λ is the wavelength, c is the speed of light, and f is the frequency.

The speed of light is approximately 3 x 10^8 m/s. Therefore, the wavelength of a microwave of 3 x 10^9 Hz frequency can be calculated as follows:

λ = 3 x 10^8 m/s/3 x 10^9 Hz

= 0.1 m.

Therefore,the wavelength of a microwave of 3 x 10^9 Hz frequency is 0.1 m.

Microwaves are electromagnetic waves that have a frequency between 300 MHz to 300 GHz and a wavelength from 1 mm to 1 m. Microwaves have a variety of uses, including communications, radar, and cooking. Microwave radiation is absorbed by water, fats, and sugars, which is why it is used for cooking.

The frequency of a microwave is usually expressed in megahertz (MHz) or gigahertz (GHz). One megahertz is equal to one million hertz and one gigahertz is equal to one billion hertz. The frequency of a microwave determines its wavelength; the higher the frequency, the shorter the wavelength.

Learn more about electromagnetic waves at :brainly.com/question/3101711

#SPJ4

8 0

1 year ago

A rocket achieves a lift-off velocity of 500.0 m/s from rest in 30.0 seconds. Calculate the average acceleration of the rocket.

Anettt [7]

Answer:

The average acceleration is 16.6 m/s² ⇒ 1st answer

Explanation:

A rocket achieves a lift-off velocity of 500.0 m/s from rest in

30.0 seconds

The given is:

→ The initial velocity = 0

→ The final velocity = 500 meters per seconds

→ The time is 30 seconds

Acceleration is the rate of change of velocity of the rocket

→ $a=\frac{v-u}{t}$

where a is the acceleration, v is the final velocity, u is the initial velocity

and t is the time

→ u = 0 , v = 500 m/s , t = 30 s

Substitute these values in the rule

→ $a=\frac{500-0}{30}=\frac{500}{30}=16.6$ m/s²

<em>The average acceleration is 16.6 m/s²</em>

6 0

3 years ago