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Ray Of Light [21]

2 years ago

9

James is planning a science fair project on sound waves. He places an alarm inside a jar which he can remove the

1 answer:

otez555 [7]2 years ago

3 0

Answer: c

Explanation:

Sound waves cannot travel through a medium

You might be interested in

How long does it take to change a flat plain into mountains? help

Len [333]

Im not for sure but i think it takes a couple hundred years (or according to the climate)

5 0

3 years ago

Read 2 more answers

A 180 g model airplane charged to 18 mC and traveling at 2.2 m/s passes within 8.6 cm of a wire, nearly parallel to its path, ca

viva [34]

Answer:

$a=0.2*10^{-5}g$

Explanation:

From the question we are told that:

Mass $M=180=>0.18kg$

Charge $Q=18mC=18*10^-^3C$

Velocity $v=2.2m/s$

Length of Wire $L=8.6cm=>0.086$

Current $I=30A$

Generally the equation for Magnetic Field of Wire B is mathematically given by

$B=\frac{\mu_0*I}{2\pi*l}$

$B=\frac{4*3.14*10^-^7*I}{2*3.14*8.6}$

$B=6.978*10^{-5}T$

Generally the equation for Force on the plane F is mathematically given by

$F=qvB$

Therefore

$ma=qvB$

$a=\frac{qvB}{m}$

$a=\frac{18*10^{-5}83.4*6.978*10^{-5}}{0.18kg}$

$a=2.37*10^{-5}$

Therefore in Terms of g's

$a=\frac{2.37*10^{-5}}{9.8}$

$a=0.2*10^{-5}g$

8 0

2 years ago

1200kg car speeds up from 2 m/s to 6 m/s. How many times greater is the car's kinetic

Bezzdna [24]

Answer:

9 times as great

Explanation:

KE = 1/2mv²

1/2(1200)(2)² = 2,400 J
1/2(1200)(6)² = 21,600 J

21,600 / 2,400 = 9

3 0

2 years ago

A dog, with a mass of 10.0 kg, is standing on a flatboat so that he is 22.5 m from the shore. He walks 7.8 m on the boat toward

marissa [1.9K]

Answer:16.096

Explanation:

Given

mass of dog $\left ( m_d\right )=10kg$

mass of boat $\left ( m_b\right )=46kg$

distance moved by dog relative to ground= $x_d$

distance moved by boat relative to ground= $x_b$

Distance moved by dog relative to boat=7.8m

There no net force on the system therefore centre of mass of system remains at its position

0= $m_d\times x_d+m_b\dot x_b$

0= $10\times x_d+46\dot x_b$

$x_d=-4.6x_b$

i.e. boat will move opposite to the direction of dog

Now

$|x_d|+|x_b|=7.8$

substituting $x_d$ value

$5.6|x_b|=7.8$

$|x_b|=1.392m$

$|x_d|=6.4032m$

now the dog is 22.5-6.403=16.096m from shore

4 0

2 years ago

One atom has 14 neutrons. Another has 13 neutrons. Both have 13 protons. These atoms are...

agasfer [191]

Hello!

These atoms are isotopes

Isotopes are atoms with the same number of protons (which determine the atomic number) and a different number of neutrons. These two atoms have the same number of protons (13), but a different number of neutrons, so they are isotopes.

According to their number of protons, these are Aluminum isotopes: ²⁷Al (stable), and ²⁶Al (radioactive), respectively.

Have a nice day!

7 0

2 years ago