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2 years ago

I need help with questions 4 and 5 because my teacher is not good with explaining them to a better understanding (Geometry)

Physics

1 answer:

Helga [31]2 years ago

4 0

Hello! I can help you with this!

4. For this problem, we have to write and solve a proportion. We would set this proportion up as 12/15 = 8/x. This is because we're looking for the length of the shadow and we know the height of the items, so we line them up horizontally and x goes with 8, because we're looking for the shadow length. Let's cross multiply the values. 15 * 8 = 120. 12 * x = 12. You get 120 = 12x. Now, we must divide each side by 12 to isolate the "x". 120/12 is 10. x = 10. There. The cardboard box casts a shadow that is 10 ft long.

5. For this question, you do the same thing. This time, you're finding the height of the tower, so you would do 1.2/0.6 = x/7. Cross multiply the values in order to get 8.4 = 0.6x. Now, divide each side by 0.6x to isolate the "x". 8.4/0.6 is 14. x = 14. There. The tower is 14 m tall.

If you need more help on proportions and using proportions in real life situations, feel free to search on the internet to find more information about how you solve them.

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If your front lawn is 21.0 feet wide and 20.0 feet long, and each square foot of lawn accumulates 1350 new snowflakes every minu

ziro4ka [17]

Answer:

snow is 64.638 kg / hr

Explanation:

Given data

wide w = 21 feet

long L = 20 ft

area A = 1350 square foot

mass of snow m = 1.90 mg

to find out

snow in kilograms / hour

solution

we will find snow in kg

so we apply formula that is

snow kg / hour = w × L ×A × m × 60/10^6

put all value we get snow

snow = 21 × 20 × 1350 × 1.90 × 60/10^6

snow = 420 × 1350 × 1.90 × 60/10^6

snow = 1077300 × 60/10^6

snow = 64.638

hence snow is 64.638 kg / hr

7 0

2 years ago

Which statement best supports the claim that there is such a thing as a perfect pitch?

givi [52]

I would say the answer is B

Hope it helps!

5 0

3 years ago

Question 1

galina1969 [7]

1/f= 1/di+1/do
1/f=1/90m+1/40m
1/f ≈27.7m

7 0

2 years ago

Madelyn wanted to learn what sorts of things around the house are magnetic. She took a magnet around and touched it to many thin

madreJ [45]

Answer:

Explanation:

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7 0

2 years ago

An unruly student with a spitwad (a lump of wet paper) of mass 20 g in his pocket finds himself in the school library where ther

jeka94

Answer:

T = 188.5 s, correct is C

Explanation:

This problem must be worked on using conservation of angular momentum. We define the system as formed by the fan and the paper, as the system is isolated, the moment is conserved

initial instant. Before the crash

L₀ = r m v₀ + I₀ w₀

the angular speed of the fan is zero w₀ = 0

final instant. After the crash

L_f = I₀ w + m r v

L₀ = L_f

m r v₀ = I₀ w + m r v

angular and linear velocity are related

v = r w

w = v / r

m r v₀ = I₀ v / r + m r v

m r v₀ = (I₀ / r + mr) v

v = $\frac{m}{\frac{I_o}{r} +mr} \ r v_o$

let's calculate

v = $\frac{0.020}{\frac{1.4}{0.6 } + 0.020 \ 0.6 } \ 0.6 \ 4$

v = $\frac{0.020}{2.345} \ 2.4$

v = 0.02 m / s

To calculate the time of a complete revolution we can use the kinematics relations of uniform motion

v = x / T

T = x / v

the distance of a circle with radius r = 0.6 m

x = 2π r

we substitute

T = 2π r / v

let's calculate

T = 2π 0.6/0.02

T = 188.5 s

reduce

t = 188.5 s ( 1 min/60 s) = 3.13 min

correct is C

6 0

2 years ago