The mass number of iodine is 126, and it’s in the 53rd place in the periodic table. It has

if 130N centripetal force is needed to keep a 0.45kg ball that is attached to a string that is 0.7m long to complete 5 full rota

andrezito [222]

Answer:

centripetal acceleration of the ball is 6.9 m/s/s

tangential speed of the ball is 2.2 m/s

Explanation:

As we know that ball complete 5 rotations in 10 seconds

so frequency of rotation of ball is given as

$f = \frac{5}{10} = 0.5 Hz$

now we know that angular frequency is given as

$\omega = 2\pi f$

$\omega = 2(\pi)(0.5)$

$\omega = \pi rad/s$

Now centripetal acceleration is given as

$a_c = \omega^2 R$

$a_c = \pi^2 (0.7)$

$a_c = 6.9 m/s^2$

now the velocity of the ball at this angular frequency is given as

$v = R\omega$

$v = 0.7 (\pi)$

$v = 2.2 m/s$

4 0

3 years ago

I WILL GIVE BRAINLIEST Which of the following statements is true with regard to transverse and longitudinal waves?

pishuonlain [190]

Answer: Transverse waves have motion perpendicular to velocity, while longitudinal waves have motion parallel to velocity.

Explanation:

Transverse waves are characterized by the fact that the particles of the medium in which they propagate move transversely to the direction of propagation of the wave.

In other words,<u> its displacement is perpendicular to the direction of propagation of the wave</u>, being a good example the circular waves in the water.

On the other hand, Longitudinal waves are characterized by the fact that <u>the oscillation of the particles in the medium is parallel to the direction of propagation of the wave.</u> A good example of this is the sound wave.

8 0

3 years ago

A lighthouse is located on a small island, 3 km away from the nearest point on a straight shoreline, and its light makes four re

lbvjy [14]

Answer:

The beam of light is moving at the peed of:

$\frac{dy}{dt} = \frac{80\pi}{3}$ km/min

Given:

Distance from the isalnd, d = 3 km

No. of revolutions per minute, n = 4

Solution:

Angular velocity, $\omega = \frac{d\theta'}{dt} = 2\pi n = 2\pi \times 4 = 8\pi$ (1)

Now, in the right angle in the given fig.:

$tan\theta' = \frac{y}{3}$

Now, differentiating both the sides w.r.t t:

$\frac{dtan\theta'}{dt} = \frac{dy}{3dt}$

Applying chain rule:

$\frac{dtan\theta'}{d\theta'}.\frac{d\theta'}{dt} = \frac{dy}{3dt}$

$sec^{2}\theta'\frac{d\theta'}{dt} = \frac{dy}{3dt} = (1 + tan^{2}\theta')\frac{d\theta'}{dt}$

Now, using $tan\theta = \frac{1}{m}$ and y = 1 in the above eqn, we get:

$(1 + (\frac{1}{3})^{2})\frac{d\theta'}{dt} = \frac{dy}{3dt}$

Also, using eqn (1),

$8\pi\frac{10}{9})\theta' = \frac{dy}{3dt}$

$\frac{dy}{dt} = \frac{80\pi}{3}$

7 0

3 years ago

A discharge lamp rated at 25 W (1 W = 1 J/s) emits yellow light of wavelength 580 nm. How many photons of yellow light does the

Scrat [10]

Answer:

the number of photons of yellow light does the lamp generate in 1.0 s is 7 x $10^{19}$

Explanation:

given information:

power, P = 25 W

wavelength. λ - 580 nm = 5.80 x $10^{-7}$ m

time, t = 1 s

to calculate the number of photon(N), we use the following equation

N = λPt/hc

where

λ = wavelength (m)

P = power (W)

t = time interval (s)

h = Planck's constant (6.23 x $10^{-34}$ Js)

c = light's velocity (3 x $10^{8} m/s^{2}$ )

So,

N = λPt/hc

= (5.80 x $10^{-7}$ )(25)(1)/(6.23 x $10^{-34}$ )(3 x $10^{8} m/s^{2}$ )

= 7 x $10^{19}$

3 0

3 years ago

The magnitude of the weight of a 3.0 kg object on the surface of the earth is 29 N. True False

madreJ [45]

True

In fact, the weight of an object on the surface of the Earth is given by:
$F=mg$
where m is the mass of the object and $g=9.81 m/s^2$ is the gravitational acceleration on Earth's surface. If we use the mass of the object, m=3.0 kg, we find
$F=mg=(3.0 kg)(9.81 m/s^2)=29 N$

8 0

3 years ago