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
Licemer1 [7]
3 years ago
10

Can someone help me with these physics questions?

Physics
1 answer:
wariber [46]3 years ago
6 0

hi! Glad to help =)

1. would be c

2 would be d

3 would be A

You might be interested in
Describe how charge is transferred from the ruler to the metal rod.
spin [16.1K]
When the ruler is broughı near the inetal knob, it repels electrons in the metal. Electrons move away froni the ruler and down the metal rod. The knob now has a positive charge. The thin pieces of metal foil at the bottom of the metal rod now have a negative charge.
3 0
2 years ago
Read 2 more answers
A cellphone charger has a transformer with 2000 turns in the primary coil which converts 240v a.c to 6v a.c and a rectifier that
inn [45]

Answer:

As we are converting 220V AC into a 5V DC, first we need a step-down transformer to reduce such high voltage. Here we have used 9-0-9 1A step-down transformer, which convert 220V AC to 9V AC. In transformer there are primary and secondary coils which step up or step down the voltage according to the no of turn in the coils.

Selection of proper transformer is very important. Current rating depends upon the Current requirement of Load circuit (circuit which will use the generate DC). The voltage rating should be more than the required voltage. Means if we need 5V DC, transformer should at least have a rating of 7V, because voltage regulator IC 7805 at least need 2V more i.e. 7V to provide a 5V voltage.

5 0
2 years ago
Energy is conventionally measured in Calories as well as in joules. One Calorie in nutrition is one kilocalorie, defined as 1 kc
Sergeeva-Olga [200]

Answer:

a) The student must run flight of stairs to lose 1.00 kg of fat 709.5 times.

b) Average power

P(w)= 1062.07 [w]

P(hp)=1.42 [hp]

c) This activity is highly unpractical, because the high amount of repetitions he has to due in order to lose, just 1 Kg of fat.

Explanation:

First, lets consider the required amount of work to move the mass of the student. (considering running stairs just as a vertical movement)

Work:

W= F*d= m*g*d

Where m is the mass of the student, g is gravity (9.8 m/s) and d is the total distance going up the stairs (0.15m *85steps= 12.75m )

W= F*d= m*g*d=85* 9.8*12.75=10620.75 [J]

Converting from Joules to Kcals:

\frac{10620.75}{4186} =2.537 Kcal

Now lets take into account the efficiency of the human body (20%)

2.537 ---> 20%

 x       ---> 100%

x=\frac{2.537*100}{20} =12.685

So the student is consuming 12.685 KCals each time he runs up the stairs.

Now,

1 g --> 9 Kcals

1000 g --> 9000KCals

Burning 1 g of fat, requieres 9 KCals, 1000g burns 9000KCals. So in order to burn a 1Kg of fat:

\frac{9000Kcals}{12.685Kcals} =709.5 times

He must run up the stairs 709.5 times, to burn 1 Kg of fat.

********************

For b) just converting units, taking into account the time lapse. (53103.75 is the 100% of the energy in joules, from converting 12.685Kcals to joules)

Power=\frac{Joules}{Seconds} =\frac{53103.75}{50} =1062.075 [W]\\

P(hp)=\frac{P(w)}{745.7} =\frac{1062.075}{745.7} =1.42[hp]

*****

4 0
3 years ago
Endothermic reactions give off heat as they proceed. <br> a. True<br> b. False
Temka [501]
B. False
Endothermic reactions absorb heat.
5 0
3 years ago
Both the Moon and the Sun influence the tides on Earth. The moon has a much greater influence though. Why is that? A) because th
Temka [501]
C. The sun is 400 times farther from Earth than the moon is.
3 0
2 years ago
Read 2 more answers
Other questions:
  • A 3.0N force to the right acts on a 0.5kg object at rest during a time interval of 4.0 seconds .What is the velocity of the obje
    11·2 answers
  • One way to decrease the inertia of an object is to
    8·2 answers
  • A)If the rms value of the electric field in an electromagnetic wave is doubled, by what factor does the rms value of the magneti
    9·1 answer
  • It is necessary to develop alternative sources of energy because _____.
    11·1 answer
  • An atom has 35 protons. what element is it?
    10·2 answers
  • Tin shears have longer handles than the scissors used to cut cloth why ​
    12·1 answer
  • 100 POINTS
    12·1 answer
  • why is The sum of two vectors has the smallest magnitude when the angle between these two vectors is 180t
    5·1 answer
  • The learning about Universe is<br> called ________ ...​
    14·2 answers
  • What is an electric field? How<br> do you calculate the electric<br> field due to a point charge?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!