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3 years ago

All valid equations in physics have consistent units. Are all equations that have consistent units valid?

Physics

1 answer:

sweet [91]3 years ago

8 0

Answer:

c. No. An equation may have consistent units but still be numerically invaid.

Explanation:

For an equation to be corrected, it should have consistent units and also be numerically correct.

Most equation are of the form;

(Actual quantity) = (dimensionless constant) × (dimensionally correct quantity)

From the above, without the dimensionless constant the equation would be numerically wrong.

For example; Kinetic energy equation.

KE = 0.5(mv^2)

Without the dimensionless constant '0.5' the equation would be dimensionally correct but numerically wrong.

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What is the average horizontal component of force exerted on his feet by the ground during acceleration?

Arte-miy333 [17]

Well you have to think of it like electricity go through your answer closes to that and figure it out

7 0

3 years ago

gives the speed v versus time t for a 0.500 kg object of radius 6.00 cm that rolls smoothly down a 30° ramp. The scale on the ve

ddd [48]

Answer:

Rotational inertia of the object is given as

$I = 7.2 \times 10^{-4} kg m^2$

Explanation:

As we know that the acceleration of the object on inclined plane is given as

$a = \frac{gsin\theta}{1 + k^2/R^2}$

now we know that velocity at any instant of time is given as

$v = at$

now we know that if the graph between velocity and time is given then the slope of the graph will be same as acceleration

so here we have

$\frac{gsin\theta}{1 + k^2/R^2} = slope$

now from the graph slope of the graph is given as

$slope = \frac{3.5 - 0}{1}$

$\frac{gsin\theta}{1 + k^2/R^2} = 3.5$

$\frac{9.81 sin30}{1 + k^2/R^2} = 3.5$

$k^2 = 0.4 R^2$

now rotational inertia is given as

$I = mk^2$

$I = 0.5(0.4)(0.06)^2$

$I = 7.2 \times 10^{-4} kg m^2$

8 0

3 years ago

A particle with charge 3.20×10−19 c is placed on the x axis in a region where the electric potential due to other charges increa

lys-0071 [83]

Answer:

-5 V

Explanation:

The charged particle (which is positively charged) moves from point A to B, and its kinetic energy increases: it means that the particle is following the direction of the field, so its potential energy is decreasing (because it's been converted into potential energy), therefore it is moving from a point at higher potential (A) to a point at lower potential (B). This means that the value

vb−va

is negative.

We can calculate the potential difference between the two points by using the law of conservation of energy:

$\Delta K+ \Delta U=0\\\Delta K + q\Delta V=0$

where:

$\Delta K=+1.6\cdot 10^{-18} J$ is the change in kinetic energy of the particle

$q=3.2\cdot 10^{-19} C$ is the charge of the particle

$\Delta V =V_b-V_a$ is the potential difference

Re-arranging the equation, we can find the value of the potential difference:

$\Delta V=V_b-V_a = -\frac{\Delta K}{q}=-\frac{1.6\cdot 10^{-18} J}{3.2\cdot 10^{-19} C}=-5 V$

8 0

3 years ago

You are trying to hear your friend give directions to new store in town. But from your distance (1 point) of 15 m you only hear

Marat540 [252]

Answer:

option D

Explanation:

given,

Intensity of sound = 20 dB

distance = 15 m

intensity of sound is increased to = 50 dB

distance between the sound level = ?

Using relation

$L_2 = L_1 - |20(log \dfrac{r_2}{r_1})|$

L₁ = 20 dB L₂ = 50 dB r₁ = 15 m r₂ = ?

$log (\dfrac{r_2}{r_1}) = \dfrac{L_1 -L_2}{20}$

$\dfrac{r_2}{r_1}= 10^{\dfrac{|L_1 -L_2|}{20}}$

$r_2 =r_1 10^{\dfrac{|L_1 -L_2|}{20}}$

$r_2 =15 \times 10^{\dfrac{|20-50|}{20}}$

$r_2 =15 \times 10^{-1.5}$

r₂ = 0.47 m

r₂ = 47 cm

hence, the correct answer is option D

7 0

3 years ago

What is the trend noticed with the inner planets

lutik1710 [3]

The inner planets are closer to the Sun and are smaller and rockier. ... The outer planets are further away, larger and made up mostly of gas. The inner planets (in order of distance from the sun, closest to furthest) are Mercury, Venus, Earth and Mars.Apr 23, 2014

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3 years ago