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3 years ago

Which type of electromagnetic radiation cannot be focused?

Physics

2 answers:

Irina18 [472]3 years ago

7 0

The answer is A. Hope this helps. :)

dalvyx [7]3 years ago

5 0

(A) Gamma rays

Focussing is a process in which a beam of light is passed and concentrated on the particular point.

Gamma rays are the type of elecromagnetic radiation that cannot of focused. Gamma rays has high frequency and also are quite energetic due to which when the beam of light is passed through it, it becomes too difficult to focus on a particular point as they interacts strongly with the matter and destroys itself. Hence, Gamma rays are not easily focused.

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I have a question, it concerns hydrostatic buoyancy and Archimedes' law.

saw5 [17]

Answer: the lvl wud remain the same

Explanation: as per Archimedes Principle, the weight of the water displaced by the object is equal to the weight of the object. When the ship initially went into the pool, it wud hv displaced some water. When the anchor is dropped, the level does not change coz the anchor was already in the ship and no extra weight has been added, so the weight of the anchor has already been accounted for in the first place when the ship was first placed in the pool

4 0

3 years ago

What is one common product that uses microwaves

AVprozaik [17]

Electromagnet Radiation

7 0

3 years ago

The sound intensity of a certain type of food processor in normally distributed with standard deviation of 2.9 decibels. If the

Maru [420]

Answer: $(48.41,\ 52.19)$

Explanation:

The confidence interval for population mean is given by :-

$\overline{x}\pm z_{\alpha/2}\dfrac{\sigma}{\sqrt{n}}$

Given : Sample size : $n=9$

Sample mean : $\ovreline{x}=50.3\text{ decibels}$

Standard deviation : $\sigma=2.9\text{ decibels }$

Significance level : $\alpha=1-0.95=0.05$

Critical value : $z_{\alpha/2}=z_{0.025}=1.96$

Now, the 95% confidence interval estimate of the (true, unknown) mean sound intensity of all food processors of this type :-

$50.3\pm (1.96)\dfrac{2.9}{\sqrt{9}}\\\\\approx50.3\pm1.89\\\\=(50.3-1.89,\ 50.3+1.89)=(48.41,\ 52.19)$

6 0

3 years ago

You are sitting on a merry-go-round of mass 200 kg and radius 2m that is at rest (not spinning). Your mass is 50 kg. Your friend

Bogdan [553]

Answer:

a. $\tau=200J$ b. $\alpha=0.44 \frac{rad}{s^2}$ c. $\alpha=0.33\frac{rad}{s^2}$ d. The angular acceleration when sitting in the middle is larger.

Explanation:

a. The magnitude of the torque is given by $\tau=rF\sin \theta$ , being r the radius, F the force aplied and $\theta$ the angle between the vector force and the vector radius. Since $\theta=90^{\circ}, \, \sin\theta=1$ and so $\tau=rF=2m100N=200Nm=200J$ .

b. Since the relation $\tau=I\alpha$ hols, being I the moment of inertia, the angular acceleration can be calculated by $\alpha=\frac{\tau}{I}$ . Since we have already calculated the torque, all left is calculate the moment of inertia. The moment of inertia of a solid disk rotating about an axis that passes through its center is $I=\frac{1}{2}Mr^2$ , being M the mass of the disk. If we assume that a person has a punctual mass, the moment of inertia of a person would be given by $I_p=m_pr_p^{2}$ , being $m_p$ the mass of the person and $r_p^{2}$ the distance from the person to the center. Given all of this, we have

$\alpha=\frac{\tau}{I}=\frac{\tau}{I_{disk}+I_{person}}=\frac{Fr}{\frac{1}{2}Mr^2+m_pr_p^{2}}=\frac{200Nm}{\frac{1}{2}200kg*4m^2+50kg*1m^2}=\frac{200\frac{kgm^2}{s^2}}{450Nm^2}\approx 0.44\frac{rad}{s^2}$ .

c. Similar equation to b, but changing $r_p=2m$ , so

$alpha=\dfrac{200\frac{kgm^2}{s^2}}{\frac{1}{2}200*4kg\,m^2+50*4 kg\,m^2}=\dfrac{200}{600}\dfrac{1}{s^2}\approx 0.33 \frac{rad}{s^2}$ .

d. The angular acceleration when sitting in the middle is larger because the moment of inertia of the person is smaller, meaning that the person has less inertia to rotate.

5 0

3 years ago

When might it be harder to stop a vehicle moving at 30 km/h than one moving at 60 km/h?

rodikova [14]

Answer:

when the momentum of the vehicle moving at 30 km/h is higher than the one from the vehicle moving at 60 km/h

Explanation:

It's much harder to stop a freight truck moving at 30 km/h than a hot wheels car moving at 60 km/h.

4 0

2 years ago