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3 years ago

5

a motorcyclist starts from rest and accelerates at rate of 4 meters per second squared north. what is the final velocity of the

motorcycle if travels for 20 seconds.

1 answer:

MArishka [77]3 years ago

8 0

Answer:

80m<em>/</em><em>s</em>

Explanation:

Final velocity is given by

v=u+at

when a motorcyclist starts from rest, initial velocity (u) =0

therefore

v=0+4*20

v=80m/s

that's the answer

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It is known that the gravitational force of attraction between two alpha particles is much weaker than the electrical repulsion.

natali 33 [55]

Answer:

<em>The ratio of gravitational force to electrical force is 3.19 x 10^-36 </em>

<em></em>

Explanation:

mass of an alpha particle = 6.64 x $10^{-27}$ kg

charge on an alpha particle = +2e = +2(1.6 x $10^{-19}$ C) = 3.2 x $10^{-19}$ C

distance between particles = d

For gravitational attraction:

The force of gravitational attraction F = $\frac{Gm^{2} }{r^{2} }$

where G = gravitational constant = 6.67 x $10^{-11}$ m^3 kg^-1 s^-2

r = the distance between the particles = d

m = the mass of each particle

therefore, gravitational force = $\frac{6.67*10^{-11}*(6.64*10^{-27} )^{2} }{d^{2} }$ = $\frac{2.94*10^{-63} }{d^{2} }$ Newton

For electrical repulsion:

Electrical force between the particles = $\frac{-kQ^{2} }{r^{2} }$

where k is the Coulomb's constant = 9.0 x $10^{9}$ N•m^2/C^2

r = distance between the particles = d

Q = charge on each particle

therefore, electrical force = $\frac{-9*10^{9}*(3.2*10^{-19} )^{2} }{d^{2} }$ = $\frac{-9.216*10^{-28} }{d^{2} }$ Newton

the negative sign implies that there is a repulsion on the particles due to their like charges.

Ratio of the magnitude of gravitation to electrical force = $\frac{2.94*10^{-63} }{9.216*10^{-28} }$

==> <em>3.19 x 10^-36 </em>

8 0

3 years ago

An atom emission of light with a specific amount of energy confirms that ?

marusya05 [52]

The correct answer is B, electrons emit and absorb energy based on their position around the nucleus.

8 0

3 years ago

How come that there is a presence of cos there?

liubo4ka [24]

Answer:

Can i have more context

Explanation:

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3 years ago

Convert 23 miles into feet.<br> **There are 5280 feet in 1 mile** *

zhenek [66]

Answer:

121440 feet is 23 miles.

5280 x 23= 121440

To check your answer just divide 121440 by 5280, which gives you 23.

Hopefully this helps you!

8 0

3 years ago

By what factor must the amplitude of a sound wave be increased in order to increase the intensity by a factor of 9?a. 9 b. 2 c.

Marta_Voda [28]

Answer:

option D

Explanation:

given,

$intensity\ \alpha \ (Amplitude)^2$

increase the intensity by factor of 9

I₁ = I₀

I₂ = 9 I₀

now,

$\dfrac{I_1}{I_2}=\dfrac{A_1^2}{A_2^2}$

$\dfrac{I_0}{9I_0}=(\dfrac{A_1}{A_2})^2$

$(\dfrac{A_1}{A_2})^2=\dfrac{1}{9}$

$\dfrac{A_1}{A_2}=\dfrac{1}{3}$

A₂ = 3 A₁

hence, amplitude increase with the factor of 3

so, the correct answer is option D

4 0

3 years ago

Read 2 more answers