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3 years ago

How many atoms are there in 3.4moles if helium ,show the calculation

1 answer:

6 0

Answer: 20.4752789138x x 10^23 atoms
To count how many atoms in moles you need to know Avogadro's number. Avogadro's number dictate that for every mole there is 6.022140857 × 10^23 molecule/atoms.
Then 3.4 moles of helium will be 3.4x 6.022140857 x 10^23 atoms= 20.4752789138x x 10^23 atoms

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using newtons law a force of 250N is applied to an object that accelerates at a rate of 5M/s2 what is the mass of the object?

AURORKA [14]

Answer:

50 kg

Explanation:

F = ma

250 N = m (5 m/s²)

m = 50 kg

7 0

3 years ago

A 94 g particle undergoes SHM with an amplitude of 8.3 mm, a maximum acceleration of magnitude 7.8 x 103 m/s2, and an unknown ph

Lelechka [254]

Answer:

a) T = 6.49*10^-3 s

b) v = 8 m/s

c) E = 3 J

d) F = 733 N

e) F = 366.5 J

Explanation:

Given

Mass of particle, m = 94 g = 0.094 kg

Amplitude of the particle, A = 8.3 mm = 8.3*10^-3 m

Maximum acceleration of particle, a = 7.8*10^3 m/s²

the equation describing Simple Harmonic Motion is given as

x = A cos (wt +φ)

To fond the acceleration of this relationship, we would have to integrate. Twice, the first would be a Velocity, and the second acceleration that we need.

Velocity = dx/dt = -Aw sin(wt + φ)

Acceleration = d²x/dt = -Aw² cos(wt + φ)

From the question, we were given, magnitude of acceleration to be 7.8*10^3 m/s²

Aw² = 7.8*10^3

w² = 7.8*10^3 / A

w² = 7.8*10^3 / 8.3*10^-3

w² = 939759

w = √939759

w = 969

Recall, T = 2π/w, so that

T = (2 * 3.142) / 969

T = 6.49*10^-3 s

Maximum speed = Aw

Maximum speed = 8.3*10^-3 * 969

Maximum speed = 8.0 m/s

Total mechanical energy oscillator =

mgx + 1/2mx² =

1/2mv(max)² =

1/2 * 0.094 * 8² =

3 J

Maximum displacement

x = A cos(wt + φ)

For x to be maximum here, then cos(wt + φ) Must be equal to 1

Acceleration = d²x/dt² = -Aw²

And force = mass * acceleration

Force = 0.094 * 7.8*10^3

Force = 733 N

x = A cos(wt + φ), where cos(wt + φ) = 1/2

d²x/dt² = -Aw² * 1/2

d²x/dt² = 733 * 0.5

= 366.5 N

7 0

3 years ago

A car travels 48 km in 1.2 hours. What is the average speed of the car in km/hr

Alborosie

Answer:

average speed of car is 40 km/h

Explanation:

if car goes 48 km per 1.2 hours , the car goes 40 km per hour. so average speed of car is 40km/h

5 0

3 years ago

At Hoover Dam, the distance the water effectively falls before encountering the electric generators depends on the water levels

pashok25 [27]

Answer:

Explanation:

recall that power is energy carried out or work done per time

P=W/t

P=2*10^6*35

t=6*60=420S

W=Energy

E=2*10^6*35*360S

E=25200000000

Energy stored by water from rest is called potential energy. Since the water is falling from a height , we calculate potential energy as thus

E=M*g*h

Assume that the water intakes are effectively 175 m above the electric generators. How much water must pass through the generators to power 2 million 35-W Las Vegas light bulbs for 6.0 minutes?

M=mass of water

g=acceleration due to gravity 9.81m/s^2

h=height ,175m

25200000000=M*9.81*175

M= $\frac{25200000000}{175*9.81}$

M=1716.75kg

3 0

3 years ago

Volcanic Island Arcs, such as Japan, form when a(n) __________ plate is subducted below a(n) _________________ and takes seawate

MrMuchimi

Volcanic Island arcs form when an oceanic tectonic plate is subducted below a tectonic plate  taking seawater with it.

Volcanic island arcs occur offshore during volcanoes. They occur due to the subduction of an oceanic plate under another tectonic plate. Volcanic Island arcs occur mostly in ocean basins.

Due to the subduction of oceanic plates under tectonic plates, Island Arcs are found, mostly along the margins of continent.

Hence we can conclude that Volcanic Island arcs Form when an oceanic tectonic plate is subducted below a tectonic plate  taking seawater with it.

Learn more : brainly.com/question/18662349

7 0

2 years ago