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tino4ka555 [31]
3 years ago
8

Please give me 7th grade science fair ideas?

Physics
1 answer:
Tems11 [23]3 years ago
7 0
1) the electromagnetic spectrum and light 2) how the eye works and what the brain has to do with it 3) how nuclear anf atomic structures work
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When something is hit harder how does the transverse wave change?
Flura [38]
When something is hit harder just like when sound is turned up the waves become higher and more frequent like a zig zag more so then wavy.
5 0
3 years ago
An object has a mass of 50.0 g and a volume of 10.5 cm3. What is the object's density?
seraphim [82]
Volume=mass/density

volume=455.6/19.3

volume=23.6 mL

4 0
3 years ago
Two polarizers A and B are aligned so that their transmission axes are vertical and horizontal, respectively. A third polarizer
Reptile [31]

Answer:

Explanation:

Let the angle between the first polariser and the second polariser axis is θ.

By using of law of Malus

(a)

Let the intensity of light coming out from the first polariser is I'

I' = I_{0}Cos^{2}\theta     .... (1)

Now the angle between the transmission axis of the second and the third polariser is 90 - θ. Let the intensity of light coming out from the third polariser is I''.

By the law of Malus

I'' = I'Cos^{2}\left ( 90-\theta \right )

So,

I'' = I_{0}Cos^{2}\theta Cos^{2}\left ( 90-\theta \right )

I'' = I_{0}Cos^{2}\theta Sin^{2}\theta

I'' = \frac{I_{0}}{4}Sin^{2}2\theta

(b)

Now differentiate with respect to θ.

I'' = \frac{I_{0}}{4}\times 2 \times 2 \times Sin2\theta \times Cos 2\theta

I'' = \frac{I_{0}}{2}\times Sin 4\theta

7 0
3 years ago
A 45.0 kg skier testing a new competitive ski wax drops off a ledge, goes into a crouch and goes straight down a slope of 10.0◦
Neko [114]

Answer:

v = 21.03 m/s

Explanation:

given,

mass of skier = 45 kg        

the slope of the snow = 10.0◦      

coefficient of friction = 0.114  

distance traveled = 300 m      

speed = ?              

Acceleration = g sin θ - µ g Cos θ        

= 9.8 × Sin (10°) - 0.10 × 9.8 × Cos(10°)        

= 0.737 m/s²      

using equation of motion        

v² = u² + 2 a s        

v² = 0 + 2 × 0.737 × 300            

v = 21.03 m/s                  

Speed of skier's after travelling 300 m speed is  equal to 21.03 m/s

6 0
3 years ago
Which statement is true about a falling object? (Assume no
vladimir2022 [97]

I would say the answer is 3 because by falling technically the ball would be kind of moving in the air. Plus potential energy is when for example a soccer ball isnt moving

5 0
3 years ago
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