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
grin007 [14]
3 years ago
13

You just found a metallic object in a creek bed. you have found its mass to be 96.5 g, and it displaces 5mL of water. what is th

e substance?
A.) aluminum
B.)iron
C.)gold
D.)none of the above
Physics
2 answers:
MaRussiya [10]3 years ago
4 0
Judging by the density (19.3 g/ml) there's a very good chance that it could be gold.
Amanda [17]3 years ago
4 0

Answer:

C) gold

Explanation:

Given:

Mass of the object = 96.5 g

Volume of water displaced= 5 ml

Formula:

Density = \frac{Mass}{Volume} \\Density of metal =\frac{96.5 g}{5ml} = 19.3 g/ml

The known densities of Al, Fe and Au are:

Density of Al = 2.7 g/ml

Density of Iron (Fe)= 7.87 g/ml

Density of gold (Au) = 19.3 g/ml

Therefore, the metallic object is gold

You might be interested in
A 5.0-μC charge is placed at the 0 cm mark of a meter stick and a -4.0 μC charge is placed at the 50 cm mark. At what point on a
Maksim231197 [3]

Answer:

The distance from charge 5 μ C = 26.45 cm and the distance from - 4 μ C is 23.55 cm.

Explanation:

Given that

q₁ = 5 μ C

q₂ = - 4 μ C

The distance between charges = 50 cm

d= 50 cm

Lets take at distance x from the charge μ C ,the electrical field is zero.

That is why the distance from the charge - 4 μ C =  50 - x cm

We know that ,electric field is given as

E=K\dfrac{q}{r^2}

K\dfrac{5\ \mu}{x^2}=K\dfrac{4\mu }{(50-x)^2}\\\\\dfrac{5}{x^2}=\dfrac{4 }{(50-x)^2}\\\\\\5(50-x)^2=4x^2\\(50-x)^2=0.8x^2\\\\50-x =0.89x\\\ x=\dfrac{50}{1.89}\ cm\\\\\\x=26.45\ cm\\

Therefore the distance from charge 5 μ C = 26.45 cm and the distance from - 4 μ C is 23.55 cm.

3 0
3 years ago
1. A negatively charged rod is moved near the top of a positively charged electroscope. What
Xelga [282]

Answer:

A) Moves closer together

7 0
3 years ago
Complete the sentences below using the words below, you may use each word more than once
satela [25.4K]
Decreases, stays the same, increases. The volume decreases because as air is cooled, the individual molecules collectively possess less kinetic energy and the distances between them decrease, thus leading to a decrease in the volume they occupy at a certain pressure (please note that my answer only holds under constant pressure; air, as a gas, doesn't actually have a definite volume). The mass stays the same because physical processes do not create or destroy matter. The law of conservation of mass is obeyed. You're only cooling the air, not adding more air molecules. The density decreases because as the volume decreases and mass stays the same, you have the same mass occupying a smaller volume. Density is mass divided by volume, so as mass is held constant and volume decreases, density increases.
7 0
3 years ago
A refrigerator is used to cool water from 23°C to 5°C in a continuous manner. The heat rejected in the condenser is 570 kJ/min a
GenaCL600 [577]

Answer: Q=5.46 L/s

COP=2.58

Explanation:

Given that

Cp = 4.18 kJ/(kg.C

density  = 1 kg/L

Heat rejected Qr= 570 kJ/min

Power in put W= 2.65 KW

From first law of thermodynamics

U = W+ q

q = Heat absorbed

U = internal energy

W = workdone

U = 570 kJ/min  = 9.5 KW

9.5 = 2.65 + q

q = 6.85 KW

COP = q/W

COP = 6.58 / 2.65

COP=2.58

Lets take volume flow rate is Q

So mass flow rate of water m = ρ Q

q = m Cp ΔT

6.85 = 1 x Q x 4.18 ( 23-5)

Q=0.091 L/min

Q=5.46 L/s

7 0
3 years ago
The minimum frequency of light needed to eject electrons from a metal is called the threshold frequency, ν0. find the minimum en
shusha [124]
The energy carried by the incident light is
E=hf
where h is the Planck constant and f is the frequency of the light. The threshold frequency is the frequency that corresponds to the minimum energy needed to eject the electrons from the metal, so if we substitute the threshold frequency in the formula, we get the minimum energy the light must have to eject the electrons:
E=hf=(6.63 \cdot 10^{-34}Js)(5.64 \cdot 10^{14}s^{-1})=3.74 \cdot 10^{-19}J
4 0
4 years ago
Other questions:
  • Suppose that the sun shrank in size but that its mass remained the same. What would happen to the orbit of the earth?
    5·1 answer
  • A 2000 kg car is moving at 15 m/sec when it collides with a 1200 kg car sitting still. Briefly compare the impulse imparted on t
    7·1 answer
  • A changing climate has strong implications for biodiversity. Studies of fossil and pollen distribution show that species are ver
    5·2 answers
  • A box having a mass of 0.2 kg is dragged across a horizontal floor by
    7·1 answer
  • As a photon from the Sun's core interacts with an atom or ion, the photon gives up its energy to the particle. But the excited p
    14·1 answer
  • - Calculate the efficiency of the human body if a person eats a hamburger containing 7.4822 kJ of
    10·2 answers
  • How can a parked car move?
    7·1 answer
  • An object is falling under the influence of gravity in presence of air resistance . There are two forces acting on it. (i) What
    9·1 answer
  • In which diagram 1 or 2 would the person be experiencing winter? explain​
    8·1 answer
  • Name some applications of white surfaces.
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!