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3 years ago

What are dimensionless quantities??

Physics

1 answer:

bearhunter [10]3 years ago

7 0

Answer:

Characteristic numbers are dimensionless numbers used in fluid dynamics to describe a character of the flow. To compare a real situation with a small-scale model it is necessary to keep the important characteristic numbers the same. Names of these numbers were standardized in ISO 31, part 12.

Explanation:

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A gas expands and does PV work on its surroundings equal to 319 J. At the same time, it absorbs 136 J of heat from the surroundi

LiRa [457]

Answer:

The change in energy of the gas during the process is $-1.83\times 10^{2}$ joules.

Explanation:

We can represent this process by the First Law of Thermodynamics, in which gas does work on its surroundings and absorbs heat from there to describe its change in energy. In other words:

$Q_{in} - W_{out} = \Delta E$

Where:

$Q_{in}$ - Heat absorbed by the gas, measured in joules.

$W_{out}$ - Work done by the gas, measured in joules.

$\Delta E$ - Change in energy, measured in joules.

If we know that $Q_{in} = 1.36\times 10^{2}\,J$ and $W_{out} = 3.19\times 10^{2}\,J$ , the change in energy of the gas is:

$\Delta E = 1.36\times 10^{2}\,J-3.19\times 10^{2}\,J$

$\Delta E = -1.83\times 10^{2}\,J$

The change in energy of the gas during the process is $-1.83\times 10^{2}$ joules.

3 0

3 years ago

The wheel of a stationary exercise bicycle at your gym makes one rotation in 0.670 s. Consider two points on this wheel: Point P

defon

Answer:

0.938 m/s.

Explanation:

Given:

ω = 1 rev in 0.67 s

In rad/s,

1 rev = 2pi rad

ω = 2pi ÷ 0.67

= 9.38 rad/s

Rp = 10 cm

= 0.1 m

V = ω × r

= 9.38 × 0.1

= 0.938 m/s.

5 0

3 years ago

Jacki evaluated the expression below. 2 cubed (3 minus 1) + 4 (8 minus 12) = 2 cubed (2) + 4 (4) = 8 (2) + 16 = 16 + 16 = 32. Wh

Naddika [18.5K]

Answer:

Her error was that she did not subtract 12 from 8 correctly

Explanation:

Jackie did 8-12 instead of 12-8

8 0

3 years ago

How does the magnitude of the electrical force between a pair of charged particles change when they are brought to half their or

Ostrovityanka [42]

Answer:

5. Quadruple

Explanation:

The electrostatic force between two charged particles is given by:

$F=k\frac{q_1 q_2}{r^2}$

where

k is the Coulomb's constant

q1, q2 are the two charges

r is the separation between the charges

If the distance between the charges is reduced to half,

$r' = \frac{r}{2}$

So the new force will be

$F'=k\frac{q_1 q_2}{(r/2)^2}=4(k\frac{q_1 q_2}{r^2})=4F$

So, the force will quadruple.

4 0

3 years ago

A player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory

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At the highest point in its trajectory, the ball's acceleration is zero but its velocity is not zero.

<h3>What's the velocity of the ball at the highest point of the trajectory?</h3>

At the highest point, the ball doesn't go more high. So its vertical velocity is zero.
However, the ball moves horizontal, so its horizontal component of velocity is non - zero i.e. u×cosθ.
u= initial velocity, θ= angle of projection

<h3>What's the acceleration of the ball at the highest point of projectile?</h3>

During the whole projectile motion, the earth exerts the gravitational force with a acceleration of gravity along vertical direction.
But as there's no acceleration along vertical direction, so the acceleration along vertical direction is zero.

Thus, we can conclude that the acceleration is zero and velocity is non-zero at the highest point projectile motion.

Disclaimer: The question was given incomplete on the portal. Here is the complete question.

Question: Player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its trajectory

A- neither the ball's velocity nor its acceleration are zero.

B- the ball's acceleration points upward.

C- the ball's acceleration is zero but its velocity is not zero.

D- the ball's velocity points downward.

Learn more about the projectile motion here:

brainly.com/question/24216590

#SPJ1

7 0

2 years ago

What are dimensionless quantities??​

What are dimensionless quantities??