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3 years ago

Which of the following is a true statement?

Physics

2 answers:

Bad White [126]3 years ago

6 0

Answer:

c. Electromagnetic waves do not always need a medium to travel.

Explanation:

As the name suggests Electromagnetic waves consist of Electric and Magnetic fields.

Electromagnetic waves are transverse waves.

In a given medium Electromagnetic waves cannot vary in speed. However their wavelength and frequency can vary.

When an Electromagnetic wave travels through a medium It does not displace the medium. So, electromagnetic waves do not need a medium to travel.

forsale [732]3 years ago

4 0

C. Electromagnetic waves do not always need a medium to travel.

Since they are transverse waves they do not need a material medium.

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Find the voltage change when: a. An electric field does 12 J of work on a 0.0001-C charge. b. The same electric field does 24 J

kondaur [170]

Explanation:

Given that,

(a) Work done by the electric field is 12 J on a 0.0001 C of charge. The electric potential is defined as the work done per unit charged particles. It is given by :

$V=\dfrac{W}{q}$

$V=\dfrac{12}{0.0001}$

$V=12\times 10^4\ Volt$

(b) Similarly, same electric field does 24 J of work on a 0.0002-C charge. The electric potential difference is given by :

$V=\dfrac{W}{q}$

$V=\dfrac{24}{0.0002}$

$V=12\times 10^4\ Volt$

Therefore, this is the required solution.

7 0

3 years ago

PLEASE HELP!!!

crimeas [40]

Answer: potential to kinetic/mechanical

Explanation:

5 0

3 years ago

In what direction would the particles in this wave move, relative to the direction of wave travel?

Setler79 [48]

Everywhere particles dont stay in one place they move elsewhere

7 0

3 years ago

Read 2 more answers

Two students are on a balcony 19.1 m above the street. One student throws a ball, b1, vertically downward at 13.9 m/s. At the sa

tester [92]

Answer:

Part a)

$t = 2.83 s$

Part b)

Ball thrown downwards = $v_f = 23.8 m/s$

Ball thrown upwards = $v_f = 23.8 m/s$

Part c)

$d = 22.24 m$

Explanation:

Part a)

Since both the balls are projected with same speed in opposite directions

So here the time difference is the time for which the ball projected upward will move up and come back at the same point of projection

Afterwards the motion will be same as the first ball which is projected downwards

so here the time difference is given as

$\Delta y = 0 = v_y t + \frac{1}{2}at^2$

$0 = 13.9 t - \frac{1}{2}(9.81) t^2$

$t = 2.83 s$

Part b)

Since the displacement in y direction for two balls is same as well as the the initial speed is also same so final speed is also same for both the balls

so it is given as

$v_f^2 - v_i^2 = 2 a \Delta y$

$v_f^2 - (13.9)^2 = (2)(-9.81)(-19.1)$

$v_f^2 = 567.9$

$v_f = 23.8 m/s$

Part c)

Relative speed of two balls is given as

$v_{12} = v_1 - v_2$

$v_{12} = (13.9) - (-13.9) = 27.8 m/s$

now the distance between two balls in 0.8 s is given as

$d = v_{12} t$

$d = 27.8 \times 0.8$

$d = 22.24 m$

7 0

3 years ago

A scientist wants to measure the relationship between humidity in the

ICE Princess25 [194]

Answer:

Explanation:

<em>The most suitable testable question. in this case, would be that 'are there more home runs during the more humid months of the summer?'</em>

Since the aim of the investigation is to find the relationship between humidity and the number of home runs, measuring the number of home runs during the more humid months in the summer and comparing the data to the number of home runs during the less humid months in the same summer would provide the answer.

<u>Only option D raises a valid question that is relevant to the aim of the investigation.</u>

7 0

3 years ago