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3 years ago

An insulated lunch bag keeps food warm by

Physics

2 answers:

Greeley [361]3 years ago

8 0

Answer: slowing the transfer of thermal energy from the food inside the bag to the air outside the bag.

Hatshy [7]3 years ago

4 0

I believe the answer is D

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Using the work energy theorem. What is the velocity of a 850kg car after starting at rest when 13,000J of work is done to it.

Misha Larkins [42]

When the car starts moving it acquires kinetic energy.

For this problem the formula of kinetic energy is:

$\frac{1}{2}mv^2$

Where m is the mass of the car = 850kg, and v is the speed of the car.

If we consider insignificant the energy lost by friction with soil and air we can propose the following equation:

Applied energy = Kinetic energy acquired by the car.

$13000\ J = \frac{1}{2}mv^2\\\\13000\ J = \frac{1}{2}(850)v^2\\\\\frac{13000(2)}{850} = v^2\\\\v = \sqrt{\frac{13000(2)}{850}}\\\\v = 5.531 m/s$

The velocity is 5.531 m/s

3 0

3 years ago

What is the final temperature if it requires 5000 J of heat to warm 2.38892 x10-2 kg of water that starts at 5oC? Remember Cp fo

Tanya [424]

Explanation:

Hi ythere sorry do not know

3 0

3 years ago

What volume of h2 gas (in l), measured at 756 mmhg and 90 ∘c, is required to synthesize 23.0 g ch3oh?

Naddika [18.5K]

First let us calculate for the moles of CH3OH formed:

moles CH3OH = 23 g / (32 g / mol) = 0.71875 mol

We see that there are 2 moles of H2 per mole of CH3OH, so:

moles H2 = 0.71875 mol * 2 = 1.4375 mol

Assuming ideal gas behaviour, we use the formula:

PV = nRT

V = nRT / P

V = 1.4375 mol * (62.36367 L mmHg / mol K) * (90 + 237.15 K) / 756 mm Hg

V = 43.06 Liters

6 0

3 years ago

Answer pls!!

Greeley [361]

Explanation:

q= n e

6 × 10^-11 = n (1.6 × 10^-19)

n = 6×10^-11 / 1.6 × 10^-19

n= 3.75 × 10⁸ electrons

4 0

3 years ago

Two drums of the same size and same height are taken.

Gelneren [198K]

Answer:

i) The pressure acting on the base of B will be half the pressure acting on the base of A

ii) The pressure acting on the base of B will be the same as the pressure acting on the base of A

iii) The pressure on the base of drum A will be slightly less than the pressure on the base of drum B

Explanation:

The pressure acting on the base of the drum, P = h·ρ·g

Where;

h = The level of the liquid in the drum

$h_{max}$ = The height of the drums

ρ = The density of the liquid in the drum

g = The acceleration due to gravity ≈ 9.81 m/s²

i) If A is completely filled, we have $h_A$ = $h_{max}$

Therefore, $P_A$ = $h_{max}$ × $\rho_{liquid}$ ×g

If B is half filled, we have, $h_B$ = (1/2)· $h_{max}$

$P_B$ = (1/2) × $h_{max}$ × $\rho_{liquid}$ ×g

Therefore, $P_B$ = (1/2) × $P_A$

The pressure acting on the base of B will be half the pressure acting on the base of A

ii) If both A and B are each filled with water (the same liquid), then the pressure on their bases will be $P_A$ = $h_{max}$ × $\rho_{water}$ ×g = $P_B$ , the same, given that the acceleration due to gravity, g, is constant and the same in Nepal and India

iii) If A is filled with water, and B is filled with salty water, we have that, the density of salty water is slightly higher than water, therefore, we get;

$P_A$ = $h_{max}$ × $\rho_{water}$ ×g < $P_B$ =

The pressure on the base of drum A will be less than the pressure on the base of drum B.

3 0

3 years ago