PHYSICS
HIGH SCHOOL

Answer:

Answer:

Explanation:

Given that:

- moment of inertia of tucked body,

- rotational speed of the body,

- i.e.

- moment of inertia of the straightened body,

Now using the law of conservation of angular momentum:

angular momentum of tucked body=angular momentum of straight body

HIGH SCHOOL

A cow walks 40 m east to rest under a tree. Later, she walks 25 m north to eat a patch of clover. What is the magnitude of her displacement? A. 31.2 m

B. 47.2 m

C. 65 m

D. 90 m

This is a right triangle so use the a^2 + b^2 = c^2

40^2 + 25^2 = c^2

1600 + 625 = c^2

2225 = c^2

c = 47.17 or C

40^2 + 25^2 = c^2

1600 + 625 = c^2

2225 = c^2

c = 47.17 or C

B 47.2m displaced

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MIDDLE SCHOOL

Silvia is driving at the speed limit of 25m/s when she sees an ambulance approaching in her rearview mirror. To move out of its way, she accelerates to 32 m/s in 3 seconds. What was her acceleration.

a = ∆v/t = (32 - 25) / 3 = 7/3 m/s2

HIGH SCHOOL

a ball is whirled on a string and then the string breaks. what causes the ball to move off in a straight line ?

It would be called Inertia

It will continue in a straight line.

COLLEGE

Suppose a man's scalp hair grows at a rate of 0.49 mm per day. What is this growth rate in feet per century?

Answer:

58.703 ft/centuri

Explanation:

Length of the hair grow, l = 0.49 mm

Time to grow, t = 1 day

Convert mm into feet.

We know that, 1 mm = 0.00328 feet

So, 0.49 mm = 0.49 x 0.00328 = 0.0016072 ft

Convert day into century.

We know that, 1 century = 36525 days

So, 1 day = 1 / 36525 centuri

growth rate of hair =

= 58.703 ft/centuri

HIGH SCHOOL

Which unit is part of the SI system? gram

pint

quart

gallon

Answer:

Gram.Explanation:

The SI system refers to the International System of Units and it's the most used around the globe. The use of this system is due to the necessity of using the same units in researches from different countries.

This system was first call the MKS system (Meter-Kilogram-Second). The SI system uses these fundamental magnitud units too, meter for length, kilogram for mass and second for time.

Therefore, the right answer here is gram, because it's the base of kilogram which is used in the SI system.

The unit from the SI system would be A) Gram

MIDDLE SCHOOL

Is there more than one universe that can be explained?

No. We don't know of the existence of another universe besides

the one we live in, and we can't even explain THIS one.

Answer:

Explanation:

The Multiverse theory is not proven and we do not have any knowledge about the existence of more than one universe. We cannot explain this.

MIDDLE SCHOOL

Would you expect light to bend if it entered corn oil at an angle after it traveled through glycerol? Explain.

If their respective indices of refraction are the least bit different, then it bends (refracts). I'll leave it to you to look up the numbers.

I think No is the answer

MIDDLE SCHOOL

If a book is knocked off a desk that is .75 m tall at a rate of 2.0 m/s, how far away from the desk does it fall

Answer: 0.8 m

Explanation:

In the vertical direction, the speed is zero, u = 0.

Distance covered in the vertical direction, s = 0.75 m.

The book would fall with acceleration due to gravity in the vertical direction, a = g = 9.8 m/s²

From the equation of motion,

s = u t + 0.5 a t²

Substituting the above values, we will find out the time taken for the book to hit the ground.

⇒0.75 m=0+0.5×9.8 m/s²×t²

⇒t = √0.153 = 0.39 s ≈ 0.40 s

Now, the horizontal distance covered,

d = v×t ⇒d= 2.0 m/s × 0.40 s =0.8 m

Hence, the book falls 0.8 m away from the desk.

HIGH SCHOOL

In the light reactions, electrons from _______ replenish chlorophyll molecules that have given up electrons.

Answer: water

The light reactions of noncyclic photophosphorylation takes place in the chloroplast. The light energy is converted to chemical energy to produce both ATP and NADPH, which act as energy-transfer molecules in the light-independent reactions of the Calvin cycle. The addition of phosphate due to synthesizing of ATP by cells results to photophosphorylation.

Moreover, the electrons from water replenish chlorophyll molecules that have given up electrons by photolysis. The two electrons from the water molecule are kept in photosystem II, while the 2H+ and 1/2O2 are left out for further use.

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