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
Andrew [12]
3 years ago
11

how long does it take a 750watt heater operating at full rating to rais the temperature of 1kg of water From 40°C to 70°C {S.H.C

=4200j/kg/k and neglecte heat loss}​
Physics
1 answer:
siniylev [52]3 years ago
6 0

Answer:

168 seconds (2 min 48 s)

Explanation:

Find the heat absorbed by the water.

q = mCΔT

q = (1 kg) (4200 J/kg/K) (70°C − 40°C)

q = 126,000 J

Power is energy per time.

P = q / t

750 W = 126,000 J / t

t = 168 s

It takes 168 seconds (2 min 48 s).

You might be interested in
Three cars (car F, car G, and car H) are moving with the same velocity when the driver suddenly slams on the brakes, locking the
nika2105 [10]

Answer:

a) Option D

b) Option A

Explanation:

a) Option D

Because a massive car will have more inertia which will make the car move faster but a massive car simultaneously will have more friction thereby restricting its movement in the forward direction. Hence, all the three cars will move equal distance.

b) Option A, Car F

Being most massive car, the frictional force required to stop the car will be highest.  

4 0
2 years ago
A 100 N force is applied to move an object a horizontal distance of 5 meters at constant speed in 10 seconds. How much power is
Tpy6a [65]

Answer:

50 W

Explanation:

<h3><u>Given :</u></h3>

  • Force applied = 100 N
  • Distance covered = 5 metres
  • Time = 10 seconds

<h3><u>To find :</u></h3>

Power

<h3><u>Solution :</u></h3>

For calculating power, we first need to know about the work done.

\bf \boxed{Work = Force \times displacement}

Now, substituting values in the above formula;

Work = 100 × 5

= 500 Nm or 500 J

We know that,

\bf \boxed{Power=\dfrac{Work\:done}{Time\: taken}}

Substituting values in above formula;

Power = 500/ 10

= 50 Nm/s or 50 W

Hence, power = 50 W .

5 0
3 years ago
The diameter of a copper atom is approximately 2.28e-10 m. The massof one mole of copper is 64 grams. Assume that the atoms area
KIM [24]

1) Mass of one copper atom: 1.063\cdot 10^{-22} kg

2) There are 9.33\cdot 10^{24} atoms in the cube

3) Mass of the cubical block: 992 kg

Explanation:

1)

We are told here that the mass of one mole of copper is

M=64 g

for

n=1 mol (number of moles)

We also know that the number of atoms inside 1 mole of substance is equal to Avogadro number:

N_A = 6.022\cdot 10^{23}

This means that N_A atoms of copper have a mass of M = 64 g. Therefore, we can find the mass of one copper atom by dividing the total mass by the avogadro number:

m=\frac{M}{N_A}=\frac{64}{6.022\cdot 10^{23}}=1.063\cdot 10^{-22} kg

2)

We are told that the diameter of a copper atom is

d=2.28\cdot 10^{-10} m

We can assume that the atoms are arranged in a cube, and that they are all attached to each other; so the side of the cube can be written as size of one atom multiplied by the number of atom per side:

L=Nd

where

N is the number of atoms (rows) in one side of the cube

Since the side of the cube is

L = 4.8 cm = 0.048 m

We find N:

N=\frac{L}{d}=\frac{0.048}{2.28\cdot 10^{-10}}=2.11\cdot 10^8

This is the number of atom rows per side; therefore, the total number of atoms in the cube is

N^3=(2.11\cdot 10^8)^3=9.33\cdot 10^{24}

3)

The total mass of the cubical block of copper will be given by the mass of one atom of copper multiplied by the total number of atoms, so:

M= N^3 m

where:

N^3 = 9.33\cdot 10^{24} is the number of atoms in the cube

m=1.063\cdot 10^{-22} kg is the mass of one atom

Therefore, substituting, we find:

M=(9.33\cdot 10^{24})(1.063\cdot 10^{-22})=992 kg

So, the mass of the cubical block is 992 kg.

Learn more about mass and density:

brainly.com/question/5055270

brainly.com/question/8441651

#LearnwithBrainly

3 0
2 years ago
If the emf produced in a wire is 0.88 volts and the wire moves perpendicular to a magnetic field of strength 0.075 newtons/amper
Elza [17]
Emf = d (phi-B) / dt 
<span>B dA/dt, where dA/dt is the area swept out by the wire per unit time. </span>
<span>0.88 V = (0.075 N/(A m)) (L)(4.20 m/s), so </span>
<span>L = (0.88 J/C) / [ (0.075 N s/C m)(4.2 m/s) ] = about 3 meters</span>
6 0
2 years ago
Read 2 more answers
- A ship's total weight is equal to the weight of the water it displaces. If you want to calculate the
frosja888 [35]

Answer:

c. the volume of the part of the ship that lies below the water's surface.

Explanation:

As stated in the problem, Archimedes' Principle tells us that that buoyant force on an object is equal to the weight of fluid it displaces.  The volume of water that a ship displaces is the volume it occupies below the surface.

5 0
3 years ago
Other questions:
  • 1. Calculate the velocity of a 0.8 kg kitten with a forward momentum of 5 kg*m/s.
    12·1 answer
  • A 2.5kg metal bar is quenched from 800°C by immersion in a closed insulated tank of water containing 50 litres of water initiall
    6·1 answer
  • Which of the following is the correct SI unit to use in measuring the mass of a boulder
    5·2 answers
  • When the starter motor on a car is engaged, there is a 290 A current in the wires between the battery and the motor. Suppose the
    10·1 answer
  • Which term describes the upward force that acts on an object submerged in a fluid?
    9·2 answers
  • 7) What is the relationship between period and cycles?
    6·1 answer
  • A student is considering doing a complete repeated measures design experiment involving motor skills. The student's advisor has
    14·1 answer
  • A toy helicopter has a mass of .25 kg. The rotors of the helicopter exert an upward lift
    12·1 answer
  • A spider accelerates from a standstill to 5m/s in 10s. What is its acceleration?
    5·1 answer
  • a An object is tarown up with a velocity v = 6.02 +7.0j. Calculate the (1) time taken reach the maximum height (ii) the horizont
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!