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3 years ago

What are the 3 base units of measurement ?

1 answer:

8 0

In the SI (International, metric) system of measurement, they are the Kilogram of mass, the Meter of length, and the Second of time.

With mass, length, and time, you can combine them in enough ways to measure ALMOST everything that can be measured in the physical world, like speed, velocity, acceleration, momentum, area, volume, force, energy, pressure, etc.

'Almost'. You still need a few more to wrap things up. The other quantities (and their SI units) are: Electric charge (the Coulomb), temperature (the Kelvin), amount of a substance (the Mol), and luminous intensity (the Candela). You can't build these with only mass, length, and time.

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Early cameras were little more than a box with a pinhole on the side opposite the film. (a) What angular resolution would you ex

ollegr [7]

Answer:

angular resolution = 0.07270° = 1.269 × $10^{-3}$ rad

greatest distance from the camera = 118.20 m = 0.118 km

Explanation:

given data

diameter = 0.50 mm = 0.5 × $10^{-3}$ m

distance apart = 15 cm = 15× $10^{-2}$ m

wavelength λ = 520 nm = 520 × $10^{-9}$ m

to find out

angular resolution and greatest distance from the camera

solution

first we expression here angular resolution that is

sin θ = $\frac{1.22* \lambda }{D}$ .......................1

put here value λ is wavelength and d is diameter

we get

sin θ = $\frac{1.22*520*10^{-9}}{0.5*10^{-3}}$

θ = 0.07270° = 1.269 × $10^{-3}$ rad

and

distance from camera is calculate here as

θ = $\frac{I}{r}$ .................2

I = $\frac{15*10^{-2}}{1.269*10^{-3}}$

I = 118.20 m = 0.118 km

3 0

3 years ago

330 grams of boiling water (temperature 100°C, specific heat capacity 4.2 J/K/gram) are poured into an aluminum pan whose mass i

Alexus [3.1K]

Answer:

T = 74°C

Explanation:

Given Mw = mass of water = 330g, Ma = mass of aluminium = 840g

Cw = 4.2gJ/g°C = specific heat capacity of water and Ca = 0.9J/g°C = specific heat capacity of aluminium

Initial temperature of water = 100°C.

Initial temperature of aluminium = 29°C

When the boiling water is poured into the aluminum pan, heat is exchanged and after a short time the water and aluminum pan both come to thermal equilibrium at a common temperature T.

Heat lost by water equal to the heat gained by aluminium pan.

Mw × Cw×(100 –T) = Ma × Ca × (T–29)

330×4.2×(100– T) = 890×0.9×(T–29)

1386(100 – T) = 801(T –29)

1386/801(100 – T) = T – 29

1.73(100 – T) = T – 29

173 –1.73T = T –29

173+29 = T + 1.73T

202 = 2.73T

T = 202/2.73

T = 74°C

6 0

4 years ago

If nothing is faster than light, how did the dark get there first? O.o

erastova [34]

Nothing is faster than light. Dark is the absence of light, or indeed anything at all. ... Darkness came before light, so light had to be created to get there. It's like turning on s flashlight in a dark room: the darkness is already there, and an outside source (you/the flashlight) needs to create light.

4 0

3 years ago

Read 2 more answers

Dark matter has been detected by its

Zinaida [17]

Dark matter has been detected by its gravitational pull.

7 0

4 years ago

On which principal is the thermometer based

olchik [2.2K]

Answer:

thermometer is based on the principle of thermal expansion.

4 0

4 years ago