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
timofeeve [1]
3 years ago
12

Archimedes supposedly was asked to determine whether a crown made for the king consisted of puregold. According to legend, he so

lved this problem by weighing the crown first in air and then in water. Suppose the scale read 7.84 N with the crown in air and 6.84 N when it was in water. What should Archimedes have told the king
Physics
1 answer:
DENIUS [597]3 years ago
4 0

Answer:

the crown was not made of pure gold

Explanation:

Mass of gold = weight in air/ g = 7.84N/10ms-2= 0.784 Kg or 0.8Kg

From Archimedes principle:

Upthrust= weight in air- weight in a fluid

Upthrust= volume × density × g

Note density of water = 1000kgm-3

7.84-6.84= V × 1000kgm-3×10ms-2

V= 1/10000= 1×10-4 m^3

Density = mass/ volume= 0.8/1×10-4

= 8×10^3 Kgm-3

But we know the density of gold to be 19.3 ×10^3 kgm-3

Hence the crown was not made of pure gold

You might be interested in
The radius of Earth is . The average Earth-Sun distance is . How many Earths would fit between Earth and the Sun if they are sep
Verdich [7]

Answer:

The radius of the earth is 6,371 km.

The average Earth-Sun distance is 152.09 million km

How many Earths would fit between Earth and the Sun if they are separated by their average distance? Approximately 11,936 Earths.

I didn't really understand the last part, but if you don't get a better answer please mark me as brainliest.

6 0
2 years ago
Match the terms to the correct descriptions.
Ulleksa [173]
2. kinetic energy: due to it being transferred through collisions
5 0
3 years ago
Read 2 more answers
Light travels 3,00,000km/s. ls it right velocity or speed?​
MrRa [10]

Answer:

speed

Explanation:

because speed is fast

6 0
3 years ago
Read 2 more answers
A kite 40 ft above the ground moves horizontally at a constant speed of 10 ft/s, with a child, holding the ball of kite string,
Lorico [155]

Answer:

 v = 27.28 m /s, θ = 63.9º

Explanation:

For this exercise we can approximate the movement to a projectile launch, let's analyze the situation.

* We must find the horizontal speed, for this we will find the descent time and the horizontal distance

* We look for the vertical speed

At the highest point the speed is horizontal

Let's find the time it takes for the kite to reach the ground

             y = y₀ + v_{oy} t - ½ g t²

             0 =y₀ + 0 -1/2 gt²

             t = \sqrt{ \frac{2y_o}{g} }

             t = √(2 40/32)

             t = 2.5 s

to find the horizontal velocity we must know the horizontal distance, let's use trigonometry

          sin θ = y / l

          θ = sin⁻¹1 y / l

          θ = sin⁻¹ 40/50

          θ = 53.1º

therefore the horizontal distance is

          x = l cos 53.1

          x = 50cos 53.1

          x = 30 m

let's use the equation

          x = v₀ₓ t

          v₀ₓ = x / t

          v₀ₓ = 30 / 2.5

          v₀ₓ = 12 m / s

we look for the vertical component of the velocity

          v_y = v_{oy} - g t

          v_y = 0 - g t

          v_y = - 9.8 2.5

          v_y = -24.5 m / s

the negative sign indicates that the speed is directed downwards, because it is the arrival point, as they indicate that there is no friction, the exit speed is the same, worse with the opposite sign

We already have the two components of the velocity, let's use the Pythagorean theorem to find the modulus

          v = \sqrt{v_x^2 + v_y^2}

          v = \sqrt{12^2 + 24.5^2}

          v = 27.28 m /s

we use trigonometry for the angle

          tan θ = v_y / vₓ

          θ = tan⁻¹ v_y / vₓ

          θ = tan⁻¹ 24.5 / 12

          θ = 63.9º

4 0
3 years ago
An airplane is heading due south at a speed of 560 km/h . If a wind begins blowing from the southwest at a speed of 80.0 km/h (a
polet [3.4K]

Answer:

the magnitude of Vpg = 493.711 km/h

Explanation:

given data

speed Vpg = 560 km/h

speed Vwg = 80 km/h

solution

we get here magnitude of the plane velocity w.r.t. ground is

we know that the Vpg = Vpw + Vwg       .....................1

writing the component of the velocity that is

Vpw = (0 km/h î - 560 km/h j )

Vwg = (80 cos 45 km/h î + 80 sin 45 km/h j)

adding these

Vpg = (0+80 cos 45 km/h ) î  + ( -560 + 80 sin 45 km/h j)i

Vpg = (42.025 )  î  (-491.92 km/h)j

now we take magnitude

the magnitude of Vpg = \sqrt{(42.025^2+(-491.92)^2)} km/h

the magnitude of Vpg = 493.711 km/h

5 0
2 years ago
Other questions:
  • Which of the following best represents acceleration as presented on a graph?
    10·2 answers
  • How long does it take to drive from one end of california to the other?
    7·1 answer
  • A ball is thrown with a velocity of 40 m/s at an angle of 30° above the horizontal and attains a certain range R. At what other
    14·1 answer
  • What is involved in a career exploration
    15·2 answers
  • Help please I have to turn this in tonight!!
    10·2 answers
  • Plsssssss helppppppp
    13·1 answer
  • ANSWER ASAP PLS
    5·1 answer
  • What does the model below represent?
    12·1 answer
  • An 80,000 kg plane is flying at 900 km/h at a height of 10 kilometers. What is its total mechanical energy? Group of answer choi
    10·1 answer
  • A small box is held in place against a rough vertical wall by someone pushing on it with a force directed upward at 27 ∘ above t
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!