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
lukranit [14]
3 years ago
13

Rubbing your hands together warms them by converting work into thermal energy. If a woman rubs her hands back and forth for a to

tal of 12 rubs, at a distance of 7.50 cm per rub, and with a frictional force of 45.0 N, what is the temperature increase in degrees Celsius?
Physics
1 answer:
Feliz [49]3 years ago
5 0

Answer:

Explanation:

Total heat = Work done = Force × distance

distance = 0.075 × 12 = 0.9 m

W = 45 × 0.9 = 40.5 joules

Specific heat of the human hand = 3.5 kj/kg = 3.5 j/g

Q = MCΔT

ΔT = (Q) ÷ (MC)

ΔT = 40.5 ÷ (3.5 × 1) = 11.57°C

You might be interested in
If you apply an unbalanced force to this object it will ______. Mention all that will apply: change velocity, accelerate, change
Papessa [141]

Answer:

All of them: change velocity, accelerate, change position

Explanation:

We can answer this question by using Newton's second law:

F = ma

where

F is the net force on the object

m is the mass of the object

a is the acceleration

We notice that when there is an unbalanced force on the object, F\neq 0, and therefore

a\neq 0

whcih means that the object will accelerate.

But acceleration is the rate of change of velocity, v:

a=\frac{\Delta v}{\Delta t}

And so,

\Delta v \neq 0

which means that the object will change velocity.

If the object is changing velocity, this means that it is also moving: therefore, the position of the object must be changing, so also the option "change position" is correct.

6 0
3 years ago
A sample of copper with a mass of 1.80 kg, initially at a temperature of 150.0°C, is in a well-insulated container. Water at a t
user100 [1]

Answer:

the mass of water is 0.3 Kg

Explanation:

since the container is well-insulated, the heat released by the copper is absorbed by the water , therefore:

Q water + Q copper = Q surroundings =0 (insulated)

Q water = - Q copper

since Q = m * c * ( T eq - Ti ) , where m = mass, c = specific heat, T eq = equilibrium temperature and Ti = initial temperature

and denoting w as water and co as copper :

m w * c w * (T eq - Tiw) = - m co * c co * (T eq - Ti co) =  m co * c co * (T co - Ti eq)

m w = m co * c co * (T co - Ti eq) / [ c w * (T eq - Tiw) ]

We take the specific heat of water as c= 1 cal/g °C = 4.186 J/g °C . Also the specific heat of copper can be found in tables → at 25°C c co = 0.385 J/g°C

if we assume that both specific heats do not change during the process (or the change is insignificant)

m w = m co * c co * (T eq - Ti co) / [ c w * (T eq - Tiw) ]

m w= 1.80 kg *  0.385 J/g°C ( 150°C - 70°C) /( 4.186 J/g°C ( 70°C- 27°C))

m w= 0.3 kg

7 0
4 years ago
You are the design engineer in charge of testing the crashworthiness of new automobile models. Cars are tested by smashing them
BaLLatris [955]

Answer:

average force  is 138900 N

Explanation:

given data

speed = 50 km/h = 13.89 m/s

mass = 1500 kg

time = 0.15 s

to find out

average force

solution

we know initial velocity of car is positive

we will apply here equation to find force that is

Force x change in time that is equal to  mass x change in speed    ................1

so put here all value of mass, time and velocity in equation 1

Force x 0.15 =  1500 x ( -13.89)

force = 138900 N

so average force  is 138900 N

3 0
3 years ago
If hydrogen and helium are the most abundant elements in the unoverse , then why are living organisms composed primarily of carb
Mumz [18]

Answer:

Most of materia isnt life.

Explanation:

The living organisms (life) aren't the most abundant thing in universe.

Hydrogen and helium are present in everywhere, but life isn't.

There is no reason to think because we have a lot of a thing, the life must be made for this thing.

The organic life just can exists because some mysterious properties about carbon, that is the basic foundation of life, carbon is a special element, why? We don't know, actually, it's a huge problem for science discover why the carbon can makes life be possible and other elements can't. But we know is this element that makes life possible.

So, note there isn't relation about the quantity of a material in Universe and the life constituition. In addition, look around, organic materials are very rare in Universe, Earth is one in lots of places and in most of this places there isn't sign of life.

Even in Earth the life looks abundant, in Universe it isn't, the same way in Universe the Hydrogen and Helium are abudant, in Earth isn't soo.

3 0
3 years ago
How many atoms of each element are in the chemical formula P205?
Irina-Kira [14]

2 atoms of P (phosphorus) and 5 atoms of O (oxygen)

Explanation:

The chemical formula of a generic compound is written as

A_n B_m

where

A and B are the symbols of the elements contained in the compound

n and m are the number of atoms of each element, A and B respectively

In this problem, the compound given is

P_2 O_5

where:

- P is the symbol of the chemical element phosphorus

- O is the symbol of the chemical element oxygen

We see that the number following P is 2, so there are 2 atoms of phosphorus, while the number following O is 5, so there are 5 atoms of oxygen.

Learn more about compounds here:

brainly.com/question/10216585

brainly.com/question/2861241

brainly.com/question/10585691

#LearnwithBrainly

5 0
3 years ago
Other questions:
  • The resistance of moving surfaces produces ________?
    12·1 answer
  • Consider a car parked on a hill and pick the axis of rotation (i.e., the pivot point) to pass through the points where the front
    7·1 answer
  • Explaining Wave Speed through Different Media
    15·1 answer
  • On an appliance cord,what is the conductor and what is the insulator
    7·2 answers
  • What is the difference between forced and natural convection?
    12·1 answer
  • If atoms are made of smaller parts, why are they considered the basic unit of matter
    5·1 answer
  • A nickel (5 cent coin) has a mass of 5.0 g. How many nickels are there in a stack of nickels with a mass of 10.0 kg?
    7·1 answer
  • A generator delivers an AC voltage of the form Δv =(82 V) sin (75πt) to a capacitor. Themaximum current in the circuit is 1.00A.
    5·1 answer
  • Refer to the following illustration to answer the question
    7·1 answer
  • Explain other learning or ideas you gained about conservation of energy
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!