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
leonid [27]
3 years ago
5

Which of the following include exact numbers? a) The speed of light in a vacuum is a physical constant; to the nearest m/s, it i

s2.99792 ×108 m/s. b) The density of mercury at 25°C is 13.53 g/mL. c) There are 3600 s in 1h. d) In 2003, the United States had 50 states.
Physics
1 answer:
telo118 [61]3 years ago
3 0

Answer:

Explanation:

Exact numbers are those numbers which are known with 100% certainty  or accuracy . Numbers having decimal are generally not exact because they are a part of long drawn decimal number after rounding off  to certain places after decimal.

On the basis of this definition we can say as follows

speed of light is 2.99792 ×108 . Here the number quoted is not an exact number because it is a rounded off figure of speed of light to five digits  after decimal .

Similarly density of mercury too is rounded off to two digits after decimal

so it is also not a exact number.

There are 3600 s in 1 h . Here 3600 s is  an  exact number because one hour has been defined as 3600 s . It is not measured by any instrument.

In 2003, the United States had 50 states. Here 50 is an exact number .  

You might be interested in
Where is the frequency of ultrasound in relation to the range of human ability to hear
kykrilka [37]

Answer:

ultra sounds have frequency higher than the upper audible limit of human hearing, for healthy, young adults.

Explanation:

4 0
3 years ago
Read 2 more answers
Pls help im begging you
Lostsunrise [7]

Answer:

I think it's TRUE because forces change an object's motion but dont quote me on it ok? Cause I'm not a 100 percent sure

7 0
3 years ago
An unstable atomic nucleus has a mass of 17.010-27kg, and starts out at rest. When it decays, it the original nucleus disintegra
slega [8]

Answer:

Part a)

v = -(8.33\hat j + 9.33\hat i)\times 10^6 m/s

Part b)

E = 4.4 \times 10^{-13} J

Explanation:

As per momentum conservation we know that there is no external force on this system so initial and final momentum must be same

So we will have

m_1v_1 + m_2v_2 + m_3v_3 = 0

(5 \times 10^{-27})(6 \times 10^6\hat j) + (8.4 \times 10^{-27})(4 \times 10^6\hat i) + (3.6 \times 10^{-27}) v = 0

(30\hat j + 33.6\hat i)\times 10^6 + 3.6 v = 0

v = -(8.33\hat j + 9.33\hat i)\times 10^6 m/s

Part b)

By equation of kinetic energy we have

E = \frac{1}{2}m_1v_1^2 + \frac{1}{2}m_2v_2^2 + \frac{1}{2}m_3v_3^2

E = \frac{1}{2}(5 \times 10^{-27})(6\times 10^6)^2 + \frac{1}{2}(8.4 \times 10^{-27})(4 \times 10^6)^2 + \frac{1}{2}(3.6 \times 10^{-27})(8.33^2 + 9.33^2) \times 10^{12}

E = 9\times 10^{-14} + 6.72 \times 10^{-14} + 2.82\times 10^{-13}

E = 4.4 \times 10^{-13} J

8 0
3 years ago
How does geomagnetism help scientist understand the motion of earth’s plates?
xeze [42]

Answer:

As the "plates" on each side of ridges in the seafloor are pulled away, lava comes up from the middle, hardens and "records" the current magnetic field.

Explanation:

6 0
3 years ago
in which of the situations listed below is energy being transferred as heat to the system in order for the system to do work? In
In-s [12.5K]
The answer is option A, i think but i am not sure
5 0
3 years ago
Other questions:
  • Which two forms of energy does a hairdryer convert electric energy into? A.)chemical energy
    12·2 answers
  • You are given a copper bar of dimensions 3 cm × 5 cm × 8 cm and asked to attach leads to it in order to make a resistor.
    10·1 answer
  • Does organisms get rid of waste
    13·2 answers
  • A convex mirror, like the passenger-side rearview mirror on a car, has a focal length of -2.2 m . an object is 4.4 m from the mi
    7·1 answer
  • Recent technological developments like high-resolution satellite imagery and diagnostic positron emission tomography (PET scans)
    5·1 answer
  • A cannonball is fired horizontally from the top of a cliff. The cannon is at height H = 70.0 m above ground level, and the ball
    6·1 answer
  • Can someone please help me on thisss
    13·1 answer
  • Calcular la longitud del faldón de una Rampa de Acceso , que en planta tiene una longitud de 20 m y la pendiente es 27%.
    10·1 answer
  • Part H)
    8·1 answer
  • The SI system uses three base units. Is this true or false?
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!