All categories

4 years ago

I need help with these 2 questions pls help

Physics

1 answer:

topjm [15]4 years ago

7 0

the measure of how many a wave passes on a certain point in a certain time is

frequency

You might be interested in

An electron in a(n) __________ subshell experiences the greatest effective nuclear charge in a many-electron atom.

bixtya [17]

The electrons float around in an outer sub shell

6 0

3 years ago

A circular hole in an aluminum plate is 2.739 cm in diameter at 0.000°C. What is the change in its diameter when the temperature

prisoha [69]

Answer:

$L = 2.746 cm$

Explanation:

As we know that thermal expansion coefficient of aluminium is given as

$\alpha = 24 \times 10^{-6} per ^oC$

now we also know that after thermal expansion the final length is given as

$L = L_o(1 + \alpha \Delta T)$

here we know that

$L_o = 2.739 cm$

$\alpha = 24 \times 10^{-6}$

$\Delta T = 108 - 0= 108^oC$

now we will have

$L = 2.739(1 + 24 \times 10^{-6} (108))$

$L = 2.746 cm$

3 0

4 years ago

A string is stretched between a fixed support and a pulley a distance 111 cm apart. The tension on the string is controlled by a

kvv77 [185]

Answer:

88.8 m/s= Speed of wave propagation in the required mode.(3 loops)

Explanation:

When there are 3 loops.

the total length = L = 3 λ /2

⇒ λ = 2 L / 3 = 2 ( 1.11 ) / 3 = 0.74 m

Velocity = v = f λ = (120)(0.74) = 88.8 m/s

3 0

4 years ago

Having landed on a newly discovered planet, an astronaut sets up a simple pendulum of length 1.38 m and finds that it makes 441

Tasya [4]

The period of a simple pendulum is given by:
$T=2 \pi \sqrt{ \frac{L}{g} }$
where L is the pendulum length, and g is the gravitational acceleration of the planet. Re-arranging the formula, we get:
$g= \frac{4 \pi^2}{T^2}L$ (1)

We already know the length of the pendulum, L=1.38 m, however we need to find its period of oscillation.

We know it makes N=441 oscillations in t=1090 s, therefore its frequency is
$f= \frac{N}{t}= \frac{441}{1090 s}=0.40 Hz$
And its period is the reciprocal of its frequency:
$T= \frac{1}{f}= \frac{1}{0.40 Hz}=2.47 s$

So now we can use eq.(1) to find the gravitational acceleration of the planet:
$g= \frac{4 \pi^2}{T^2}L = \frac{4 \pi^2}{(2.47 s)^2} (1.38 m) =8.92 m/s^2$

3 0

4 years ago

George walks to a friend's house. He walks 850 meters north before he realizes he walked too far.

anyanavicka [17]

Answer:

Explanation:

In this problem we are expected to calculate the velocity of Georges movements.

Given data

Total distance covered by George= 850+250= 1100 meters

Time taken by George to cover the total distance= 25 seconds

We know that velocity is, v= distance/ time

Therefore substituting our data into the expression for velocity we have

v= 1100/ 25= 44 m/s

Hence the velocity in m/s is 44

7 0

3 years ago