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3 years ago

A person throws a tennis ball 6 m/s straight up. How long does it take for it to come back to their hand?

Physics

1 answer:

Alja [10]3 years ago

7 0

(t) = 2t = 1.22 sec. I believe ...

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Need help ASAP

VARVARA [1.3K]

Answer:

the correct one is D,

Ultraviolet, x-ray, gamma ray

Explanation:

Electromagnetism radiation are waves of energy that is expressed by the Planck relationship

E = h f

where h is the plank constant and f the frequency of the radiation.

Also the speed of light is

c = λ f

we substitute

E = h c /λ

therefore to damage the cells of the body radiation of appreciable energy is needed

microwave radiation has an energy of 10⁻⁵ eV

infrared radiation E = 10⁻² eV

visible radiation E = 1 to 3 eV

radiation Uv E = 3 to 6 eV

X-ray E = 10 eV

gamma rays E = 10 5 eV

therefore we see that the high energy radiation is gamma rays, x-rays and ultraviolet light.

When checking the answers, the correct one is D

6 0

3 years ago

the train accelerates from 30 km/h to 45 km/h in 15 secs. a. find its acceleration. b. distance it travels during this time ...

Sonbull [250]

Acceleration = v-u/t
= (45-30)/15
= 1 km/h

Distance = ut + 1/2 at^2
s = [30 x 15] + 1/2 x 1 x 15^2
= 562.5 km

Hope this helps

3 0

3 years ago

Read 2 more answers

Zeros that follow non-zero numbers and are also to the right of a decimal point are significant.

Ivenika [448]

Yes that's correct. Also zeros in between non-zero numbers are significant figures

5 0

3 years ago

Read 2 more answers

HELP ASAP! GIVING BRAINLIEST!

Blababa [14]

Answer:

1. Emma standing on top of mountain

Since she is at the rest position and at some height from the ground so here energy is due to gravitational potential energy

So we have

gravitational potential energy

$U = mgH$

2. Emma jumping down from mountain top

Due to free fall Emma will start moving with some speed in downwards direction so here we have

$KE = \frac{1}{2}mv^2$

motion energy

3. tension in rope at Emma’s lowest position

Due to stretch in the rope here position come to the lowest end and speed comes to zero so whole energy is converted into elastic potential energy

$U = \frac{1}{2}kx^2$

elastic potential energy

4. Emma bouncing back

Due to bouncing back she will again have its kinetic energy with some speed upwards

$KE = \frac{1}{2}mv^2$

motion energy

8 0

3 years ago

Read 2 more answers

Which type of cloud is often taken to be a sign of fair weather?.

Leni [432]

The cumulus cloud.......

4 0

2 years ago