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3 years ago

Which three statements about electromagnetic radiation are true?

Physics

2 answers:

grandymaker [24]3 years ago

3 0

I think that numbers one, three, and four are true

Svetllana [295]3 years ago

3 0

Answers

1)Light is a kind of electromagnetic radiation.

3)Electromagnetic radiation has no mass.

4)Electromagnetic radiation can travel through a vacuum.

Explanations

Electromagnetic waves are waves that can travel through vacuum. that is they do not require material medium for propagation.

Light is in the electromagnetic spectrum.

Electromagnetic waves can travel through a long distance. For instance, radio waves are electromagnetic radiations that travel long distances.

Electromagnetic radiations carry energy with it but no mass.

Some of the electromagnetic radiations are visible such as visible light.

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In a pool game, the cue ball, which has an initial speed of 3.0 m/s, make an elastic collision with the eight ball, which is ini

zhenek [66]

Explanation:

Given

initial speed(u)=3 m/s

mass of each ball is m

Let the cue ball is moving in x direction initially

In elastic collision Energy and momentum is conserved

Let u be the initial velocity and $v_1 , v_2$ be the final velocity of 8 ball and cue ball respectively

$\frac{mu^2}{2}+0=\frac{mv^2_1}{2}+\frac{mv^2_2}{2}$

The angle after which cue ball is deflected is given by

$\theta _1=90-40=50^{\circ}$

Conserving momentum in x direction

$mu=mv_1cos40+mv_2cos50$

$3=v_1cos40+v_2cos50$

Along Y axis

$0+0=v_1sin40-v_2sin50$

$v_1sin40=v_2sin50$

substitute the value of $v_1$

we get $v_2=1.912 m/s$

$v_1=2.27 m/s$

5 0

3 years ago

Two bicyclists were riding their bikes at a rate of 20 kilometers per hour (km/h). During the next half hour, they observed that

Ghella [55]

Answer: 4 night’s

Explanation:

3 0

3 years ago

Alcohol of mass 21g and density 0.7gcm-3 is mixed with 10g of water. Determine the density

IRINA_888 [86]

Answer:

0.775 g/cm³

Explanation:

The given parameters are;

The mass of the alcohol = 21 g

The density of the of the alcohol = 0.7 g/cm³

The mass of water with whichit is mixed = 10 g

The density of water = 1.0 g/cm³

Therefore, the mass of the mixture, m = 21 g + 10 g = 31 g

Volume = Mass/Density

The volume of the alcohol = 21 g/(0.7 g/cm³) = 30 cm³

The volume of the water = 10 g/(1.0 g/cm³) = 10 cm³

Therefore, the volume of the mixture, V = 30 cm³ + 10 cm³ = 40 cm³

The density of the mixture, ρ = (Mass, m)/(Volume, V) = m/V

∴ ρ = (31 g)/(40 cm³) = 0.775 g/cm³

The density of the mixture, ρ = 0.775 g/cm³.

3 0

3 years ago

The work done by an external force to move a -6.70 μc charge from point a to point b is 1.20×10−3 j .

ASHA 777 [7]

Answer:

108.7 V

Explanation:

Two forces are acting on the particle:

- The external force, whose work is $W=1.20 \cdot 10^{-3}J$

- The force of the electric field, whose work is equal to the change in electric potential energy of the charge: $W_e=q\Delta V$

where

q is the charge

$\Delta V$ is the potential difference

The variation of kinetic energy of the charge is equal to the sum of the work done by the two forces:

$K_f - K_i = W + W_e = W+q\Delta V$

and since the charge starts from rest, $K_i = 0$ , so the formula becomes

$K_f = W+q\Delta V$

In this problem, we have

$W=1.20 \cdot 10^{-3}J$ is the work done by the external force

$q=-6.70 \mu C=-6.7\cdot 10^{-6}C$ is the charge

$K_f = 4.72\cdot 10^{-4}J$ is the final kinetic energy

Solving the formula for $\Delta V$ , we find

$\Delta V=\frac{K_f-W}{q}=\frac{4.72\cdot 10^{-4}J-1.2\cdot 10^{-3} J}{-6.7\cdot 10^{-6}C}=108.7 V$

4 0

3 years ago

Read 2 more answers

A wave is moving at the rate of 40 cm/s. Its wavelength is 8 cm. What is the frequency of the wave?

nikitadnepr [17]

v=40 cms speed of wave

λ=8 cm wavelength

f=? frequency of wave

v=λ⋅f

40=8⋅f

f=408

f=5 s−1 is the answer

6 0

3 years ago