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3 years ago

This question is select two answers, but I don't understand why A is wrong.

Physics

1 answer:

ElenaW [278]3 years ago

3 0

Explanation:

The blocks are spinning around the center of mass, but they're also sliding horizontally. So they still have a positive displacement.

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Mesopotamians also were the first to use ___________.

rusak2 [61]

I think it may be c i learned about this last year

7 0

3 years ago

Read 2 more answers

A car moves round a circular track of radius 0.3m of two revolution per/sec find its angular velocity.

Pie

Answer:

the angular velocity of the car is 12.568 rad/s.

Explanation:

Given;

radius of the circular track, r = 0.3 m

number of revolutions per second made by the car, ω = 2 rev/s

The angular velocity of the car in radian per second is calculated as;

From the given data, we convert the angular velocity in revolution per second to radian per second.

$\omega = 2 \ \frac{rev}{s} \times \frac{2\pi \ rad}{1 \ rev} = 4\pi \ rad/s = 12.568 \ rad/s$

Therefore, the angular velocity of the car is 12.568 rad/s.

4 0

3 years ago

Estimate the wavelength of electrons that have been accelerated from rest through a potential difference of 60 kV.

ivolga24 [154]

Answer: 2.068* $10^{-14}$ m

Explanation: According to work energy-theorem , the workdone in accelerating the electron equals the energy it would give off in terms of light.

workdone= qV

energy = hc/λ

q=magnitude of an electronic charge= 1.602* $10^{-16}$

h= planck constant = 6.626* $10^{-34}$

c= speed of light =2.998* $10^{8}$

v= potential difference= 6* $10^{4}$

λ= wavelength=unknown

by making λ subject of formulae we have that

λ= $\frac{hc}{qv}$

λ = 6.626* $10^{-34}$ * 2.998* $10^{8}$ / 1.602* $10^{-16}$ * 6* $10^{4}$

λ = $\frac{19.878*10^{-26} }{9.612*10^{-12} }$

by doing the necessary calculations, we have that

λ = 2.068* $10^{-14}$ m

8 0

3 years ago

What is a Vector and a scalar?

vfiekz [6]

Scalars are quantities that are fully described by a magnitude (or numerical value) alone.
Vectors are quantities that are fully described by both a magnitude and a direction.

4 0

3 years ago

Write the realtionship between the density of a liquid and its upthrust? clarify

kipiarov [429]

Answer:

B = ρ g V_liquid

the thrust is proportional to the density of the liquid

Explanation:

The density of a liquid is defined as the relationship between the mass and the volume of the liquid

ρ = m / V

The upward push of the liquid is given by the principle of Archimedes Archimedes establishes that the push is equal to the weight of the dislodged liquid

B = W_liquid

B = m _liquid g

we substitute mass for density

B = ρ g V_liquid

therefore we see that the thrust is proportional to the density of the liquid

8 0

3 years ago