1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
disa [49]
3 years ago
14

Peter went swimming at a lake with his friends. They arrived early in the morning. Peter walked on the sand around the lake with

his bare feet. The sand is cool. At noon, when Peter walked around the lake with his bare feet, the sand is very hot. What has made the sand hot at noon?
Physics
1 answer:
lapo4ka [179]3 years ago
4 0
The sun was shining on the sand heating it up causing ot to become hot
You might be interested in
When a cyclist rides past you on the street, this is an example of
Annette [7]

Answer:

I dont know but i think it is wind energy

Explanation:

7 0
3 years ago
How much energy must be transferred out of the system as heat q to lower its temperature to 0∘c? express your answer numerically
serg [7]

Answer:

Incomplete question:

Refer to the temperature versus time graph when answering the questions in Parts C through F. A system consists of 250 of water. The system, originally at = 21.0 , is placed in a freezer, where energy is removed from it in the form of heat at a constant rate. The figure shows how the temperature of the system takes to drop to, after which the water freezes. Once the freezing is complete, the temperature of the resulting ice continues to drop, reaching temperature after an hour. The following specific heat and latent heat values for water may be helpful.

specific heat of ice (at ) = 2.10 J/g K

latent heat of fusion (ice to water phase change at ) = 333.7 J/g

specific heat of water (at ) = 4.186 J/g K

latent heat of vaporization (water to steam phase change at ) = 2256 J/g

specific heat of steam (at ) = 2.01 J/g K

Answers:

Qtotal = 237775 J

Explanation:

To solve this exercise it is necessary to know that if the system is a single phase in which there is a temperature change or if it is a phase change at a single temperature. In the first case, the following formula would be used to calculate the amount of heat:

Q₁ = mCpΔT

Here

m is the mass = 250 g

Cp is the specific heat of ice = 2.1 J/g K

ΔT = 21 - 0 = 21°C = 294 K

In this case the amount of energy is

Q₁ = 250*2.1*294 = 154350 J

In the second case, where there is a phase change at a single temperature, the amount of heat is:

Q₂ = mLf

Here

Lf = latent heat of fusion (ice to water phase change) = 333.7 J/g

Substituting:

Q₂ = 250*333.7 = 83425 J

The total heat is:

Qtotal = 154350+83425=237775 J

7 0
3 years ago
What si unit measures speed ?
dlinn [17]
Hmm doesnt soujd familiar
4 0
3 years ago
Why does increasing the number of trials increase confidence in the results of the experiment?
Paladinen [302]
It increases confidence because the more times you conduct the same experiment over and over should either prove your hypothesis right and wrong and eliminate any random occurrences that might affect your results.
8 0
3 years ago
Read 2 more answers
The force F⃗ pulling the string is constant; therefore the magnitude of the angular acceleration α of the wheel is constant for
abruzzese [7]

Answer:

The answer is "\boxed{\boxed{\omega = \sqrt{\frac{2fd}{kmr^2}}}}"

Explanation:

\to d= r \theta \\\\ \to \theta =\frac{d}{r}\\\\\to \omega^{r} - \omega_{0}^{r} = 2 \alpha \theta\\\\\to \omega^{r} = 2 \alpha \theta    - \omega_{0}^{r} \\\\\to \omega^{r} = 2  (\frac{F}{Kmr}) \frac{d}{r}\\\\\to \omega = \sqrt{\frac{2fd}{kmr^2}}

5 0
3 years ago
Other questions:
  • You are planning to make an open rectangular box from an 8-in.-by-15-in. piece of cardboard by cutting congruent squares from th
    15·1 answer
  • What is the momentum of an object that is traveling at 3 m/s and has a mass of 5 kg?
    5·1 answer
  • Ahmed kept a balloon from his birthday for several days until it began to deflate and slowly sink to the ground. He wondered how
    8·2 answers
  • What is the equivalent resistance for a parallel circuit that has two resistors: 18.0 ohms and 23.5 ohms?
    12·2 answers
  • Precise measurements of earth indicate that its polar diameter is
    6·1 answer
  • What is the maximum speed with which a 1200-kg car can round a turn of radius 90.0 m on a flat road if the coefficient of fricti
    8·1 answer
  • NEEEEEEEEEEEEEEEEEEEEEEEEEEED !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    9·2 answers
  • HELPPPPPP!!!! Jupiter has a gravity that is 2.4 times that of Earth. A person has a mass of 60kg. What is the mass of this perso
    15·1 answer
  • PLS HELP I NEED ANSWER HOMEWORK DUE SOON
    6·1 answer
  • At what angle should the roadway on a curve with a 45 m radius be banked to allow cars to negotiate the curve at 12 m/s even if
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!