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3 years ago

Please help!!!... Why does a parachute slow a person down?

1 answer:

7 0

A parachute is a device used to slow down an object that is falling towards the ground. without a parachute the gravity is more than air resistance. But, as the parachute opens, the air resistance increases.

hope this was useful

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Hey can anyone help me out in dis pls

MissTica

Answer: 1. Liquid, molecules aren't packed very closely, and take the shape of the bottom of the container 2. Gas molecules are far apart and fill the container completely

Explanation:

4 0

4 years ago

Consider a wire of a circular cross-section with a radius of R = 3.17 mm. The magnitude of the current density is modeled as J =

Sloan [31]

Answer:

The current is $I = 8.9 *10^{-5} \ A$

Explanation:

From the question we are told that

The radius is $r = 3.17 \ mm = 3.17 *10^{-3} \ m$

The current density is $J = c\cdot r^2 = 9.00*10^{6} \ A/m^4 \cdot r^2$

The distance we are considering is $r = 0.5 R = 0.001585$

Generally current density is mathematically represented as

$J = \frac{I}{A }$

Where A is the cross-sectional area represented as

$A = \pi r^2$

=> $J = \frac{I}{\pi r^2 }$

=> $I = J * (\pi r^2 )$

Now the change in current per unit length is mathematically evaluated as

$dI = 2 J * \pi r dr$

Now to obtain the current (in A) through the inner section of the wire from the center to r = 0.5R we integrate dI from the 0 (center) to point 0.5R as follows

$I = 2\pi \int\limits^{0.5 R}_{0} {( 9.0*10^6A/m^4) * r^2 * r} \, dr$

$I = 2\pi * 9.0*10^{6} \int\limits^{0.001585}_{0} {r^3} \, dr$

$I = 2\pi *(9.0*10^{6}) [\frac{r^4}{4} ] | \left 0.001585} \atop 0}} \right.$

$I = 2\pi *(9.0*10^{6}) [ \frac{0.001585^4}{4} ]$

substituting values

$I = 2 * 3.142 * 9.00 *10^6 * [ \frac{0.001585^4}{4} ]$

$I = 8.9 *10^{-5} \ A$

5 0

4 years ago

Two objects moving with the same speed may not have the same velocity. Why?

Nutka1998 [239]

Objects have the same velocity only if they are moving at the same speed and in the same direction. Objects moving at different speeds, in different directions, or both have different velocities.

4 0

1 year ago

How are sound waves similar to light waves?

Tom [10]

Answer:

Sound and light are similar in that both are forms of energy that travel in waves.

Explanation:

They both have properties of wavelength, freqency and amplitude. ... Sound can only travel through a medium (substance) while light can travel through empty space. Sound is a form of mechanical energy caused by vibrations of matter.

6 0

3 years ago

Read 2 more answers

The theory of plate tectonics describes how the Earth’s lithosphere is broken into plates and these plates move over the molten

Mumz [18]

Answer:

Explanation:

A theory can be changed when new evidence is found. A law doesn't change because it is universally a fact. It doesn't need new evidence to support it.

5 0

3 years ago