All categories

2 years ago

How does a walkie-talkie work and why do people still use them ?

2 answers:

6 0

A walkie talkie works on wires on the inside and by the battery. People still use them because they are fun and you can talk if your 6 or 10 inches away and it sounds cool!

igomit [66]2 years ago

4 0

People use them to talk faster, rather than pulling your phone out unlocking it, opening phone app, etc...you just take the walmie talkie out and push a button, and you can hear multiple people

You might be interested in

The half-life of Co-55 is 175 hours. How much of a 4000 g of Cobalt-55 sample would be left after 525 hours?

Harrizon [31]

We know that whatever amount we start with, half of it decays and forms atoms of other elements in 175 hours. So in order to figure out how much is left after 525 hours, we'll need to know how many half-lifes pass in that amount of time.

Well, (525 divided by 175) is exactly 3 half-lifes. So this will be easy.

-- After 1 half-life . . .

. . . . . 50% decays, 50% is still there.

-- After the 2nd half-life . . .

. . . . . (half of the leftover 50%) = another 25% decays, 25% is left.

-- After the 3rd half-life . . .

. . . . . (half of the leftover 25%) = another 12.5% decays, 12.5% is left.

12.5% of 4,000g = (0.125 x 4,000g) = 500 g .

============================================

Another way:

After 1 half-life, 1/2 is left.

After 2 half-lifes, 1/4 is left.

After 3 half-lifes, 1/8 is left.

1/8 of 4,000g = (4,000g/8) = 500 g .

5 0

2 years ago

The upward force acting on the wing of an airplane ir flight is called?

Elza [17]

Answer:

Lift is the upward force on the wing acting perpendicular to the relative wind and perpendicular to the aircraft's lateral axis. Lift is required to counteract the aircraft's weight.

Explanation:

7 0

2 years ago

Read 2 more answers

If a 12 kg cat is sitting 5 m up in a tree, how much PE does it have?

Helen [10]

Answer:

588 J

Explanation:

PE (potential energy) = (mass) x (gravity) x (height)

mass = 12 kg

gravity = 9.8m/s^2

height = 5 m

PE = (12) x (9.8) x (5) = 588 J (Joules)

5 0

2 years ago

A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a lar

kakasveta [241]

Answer:

$W=4037.36\ J$

Explanation:

Given:

mass of ice melted, $m=3.3\times10^{-2}\ kg$

time taken by the ice to melt, $t=5\ min=300\ s$

latent heat of the ice, $L=3.34\times 10^5\ J$

Now the heat rejected by the Carnot engine:

$Q_R=m.L$

$Q_R=0.033\times 3.34\times 10^5$

$Q_R=11022\ J$

Since we have boiling water as hot reservoir so:

$T_H=373\ K$

The cold reservoir is ice, so:

$T_L=273\ K$

Now the efficiency:

$\eta=1-\frac{T_L}{T_H}$

$\eta=1-\frac{273}{373}$

$\eta=26.81\%$

Now form the law of energy conservation:

Heat supplied:

$Q_S-W=Q_R$

where:

$Q_S=$ heat supplied to the engine

$Q_S-\eta\times Q_S=Q_R$

$Q_S(1-\eta)=Q_R$

$Q_S=\frac{11022}{1-0.2681}$

$Q_S=15059.36\ J$

Now the work done:

$W=Q_S-Q_R$

$W=15059.36-11022$

$W=4037.36\ J$

8 0

2 years ago

Explain why we see the Milky Way as a faint band of light stretching across the sky.

Veronika [31]

The Milky Way in the sky is our particular view of the inward part of the Milky Way Galaxy as seen from our location within the Galaxy's disk. Since we are part of the disk, we see a band of diffuse light that completely encircles us.

8 0

2 years ago