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3 years ago

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A projectile is launched from the ground with an initial velocity of 12ms at an angle of 30° above the horizontal. The projectil

e lands on a hill 7.5m away. The height at which the projectile lands is most nearly
A- 1.78m
B- 3.10m
C- 5.34m
D- 6.68m
E- 12.0m

2 answers:

Keith_Richards [23]3 years ago

7 0

Answer:gggffdss

Explanation:cc bbhfewaz

netineya [11]3 years ago

6 0

$vi^{2}sin2thita/g =12^{2}sin2[30]/9.8=12.7$ Answer:

Explanation:

range is given as

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A solenoid with an air core has a magnetic field pointing along its axis in the positive x direction. This solenoid is then fill

trapecia [35]

Answer:

we can say that with a smaller magnitude , the field will point is in same direction

Explanation:

we have given that

solenoid is filled with a diamagnetic material and with air, magnetic field pointing along its axis in the positive x direction

so in small magnitude, the field will point is in same direction

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3 years ago

______ involves organizing and breaking down information into easier groups to expand capacity. Rehearsal is the verbal repetiti

adell [148]

Hi!

The answers would be <u>chunking</u> & <u>short-term</u>

1. <u>Chunking </u>involves organizing and breaking down information into easier groups to expand capacity.

<h3>Explanation:</h3>

Chunking is a mental process that is observed to increase short-term memory by taking the information and categorizing it into small groups. For instance, a longer number taken as a single unit is harder to recall then when it is divided into smaller units. 235469350 is harder to instantly recall as compared to when it is chunked into 3 groups: 235 469 350.

This allows more information to be stored in, thereby increasing the capacity of the mind to store information.

2. Rehearsal is the verbal repetition of information. These techniques are especially important for the improvement of <u>short-term</u> memory.

<h3>Explanation: </h3>

Short-term memory is lost after a couple of seconds or minutes, for instance even if you chunk the information, you might not recall it after 30 seconds. Rehearsing or repetition of information, either loudly or mentally, extends the time a particular information is retained.

So you depending on the number of times you repeat the number 235 469 350, the more your short term memory improves .

Hope this helps!

6 0

3 years ago

Calculate the wavelength in centimeters of radar energy at a frequency of 10 GHz. What is the frequency in gigahertz of radar en

konstantin123 [22]

Explanation:

(a) Frequency of radar energy, $f = 10\ GHz =10^{10}\ Hz$

The relation between frequency and wavelength is given by :

$c=f\lambda$

$\lambda=\dfrac{c}{f}$

$\lambda=\dfrac{3\times 10^8}{10^{10}}$

$\lambda=0.03\ m$

or

$\lambda=3\ cm$

(b) If wavelength, $\lambda=25\ cm=0.25\ m$

$c=f\lambda$

$f=\dfrac{c}{\lambda}$

$f=\dfrac{3\times 10^8}{0.25}$

$f=1.2\times 10^9\ Hz$

or

f = 1.2 GHz

Hence, this is the required solution.

7 0

3 years ago

A student sits on a rotating stool holding two 3.09-kg masses. When his arms are extended horizontally, the masses are 1.08 m fr

schepotkina [342]

Answer:

a

The New angular speed is $w_f = 2.034 rad/s$

b

The Kinetic energy before the masses are pulled in is $KE_i = 3.101 \ J$

c

The Kinetic energy after the masses are pulled in is $KE_f = 8.192 \ J$

Explanation:

From the we are told that masses are 1.08 m from the axis of rotation, this means that

The radius $r =1.08m$

The mass is $m = 3.09\ kg$

The angular speed $w = 0.770 \ rad/sec$

The moment of inertia of the system excluding the two mass $I = 3.25 \ kg \cdot m^2$

New radius $r_{new} = 0.34m$

Generally the conservation of angular momentum can be mathematical represented as

$w_f = [\frac{I_i}{I_f} ]w_i .....(1)$

Where $w_f$ is the final angular speed

$w_i$ is the initial angular speed

$I_i$ is the initial moment of inertia

$I_f$ is the final moment of inertia

Moment of inertia is mathematically represented as

$I = m r^2$

Where I is the moment of inertia

m is the mass

r is the radius

So the Initial moment of inertia is given as

$I_i = moment \ of \ inertia \ of\ the \ two \ mass \ + 3.25 \ kg \cdot m^2$

$I_i = 2m r^2 + 3.25$

The multiplication by is because we are considering two masses

$I_i = 2 [(3.09)(1.08)^2] +3.25 = 10.46 kg \cdot m^2$

So the final moment of inertia is given as

$I_f = 2[(3.09)(0.34)^2] +3.25 = 3.96 \ kg \cdot m^2$

Substituting these values into equation 1

$w_f = [\frac{10.46}{3.96} ] * 0.77 = 2.034 \ rad/sec$

Generally Kinetic energy is mathematically represented in term of moment of inertia as

$KE = \frac{1}{2} * I * w^2$

Now considering the kinetic energy before the masses are pulled in,

$KE_i = \frac{1}{2} * I_i * w^2_i$

The Moment of inertia would be $I_i = 10.46 \ Kg \cdot m^2$

The Angular speed would be $w_i = 0.77 \ rad/s$

Now substituting these value into the equation above

$KE_i = \frac{1}{2} * (10.46) * (0.770)^2 = 3.101 J$

Now considering the kinetic energy after the masses are pulled in,

$KE_f = \frac{1}{2} * I_f * w^2_f$

The Moment of inertia would be $I_f = 3.96 \ Kg \cdot m^2$

The Angular speed would be $w_f = 2.034 \ rad/s$

Now substituting these value into the equation above

$KE_f= \frac{1}{2} *(3.96)(2.034)^2$

$= 8.192J$

8 0

3 years ago

What is the surface tension of water? of rubbing alcohol? was your prediction correct or incorrect?

kompoz [17]

Rubbing water (isopropyl alcohol) has lesser surface tension than that water.

Water possesses a surface tension of 72 dynes/cm.

Whereas rubbing alcohol has a surface tension of 23 dynes/cm.

<h3>what is surface tension?</h3>

Surface tension is the propensity of liquid surfaces at rest to shrink to the smallest possible surface area.

Because the atoms on the outside of the molecules (often hydrogens) lack strong hydrogen bonding capabilities, most organic liquids have very low surface tensions. Because isopropanol contains just 28%, OH and the remainder is CH or CH3, the linkages that hold a droplet together are few and far between.

The only substance with a higher surface tension than water is liquid mercury (450 dyne/cm).

Learn more about surface tension here:

brainly.com/question/19390213

#SPJ4

6 0

2 years ago