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IgorLugansk [536]
3 years ago
6

HELP

Physics
1 answer:
Free_Kalibri [48]3 years ago
8 0

Answer:

Explanation:

Although there is absolutely NO regard for significant digits, I can help you with this, nonetheless.

The equation for Potential Energy is PE = mgh. We have everything but the height of the ball. We have to solve for that using a one-dimensional motion equation:

v² = v₀² + 2aΔx, where Δx is our displacement (the height we need for PE). Filling in and keeping in mind that at the max height of parabolic travel, the final velocity of the object is 0:

0 = (21.5)² + 2(-9.8)Δx and

0 = 462.25 - 19.6Δx and

-462.25 = -19.6Δx so

Δx = 23.58 m. Using this as the h in our PE equation:

PE = .19(9.8)(23.58) so

PE = 43.9 J, choice C.

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When you take pictures with a camera, the distance between the lens and the film or chip has to be adjusted, depending on the di
Shalnov [3]

Answer:

Explanation:

When a camera shifts focus from a faraway object to a nearby object, the lens-to-film distance must increase. Likewise, when it shifts focus from a nearby object to a distant object, there must be an increase in the lens to film distance (that is, the image distance).

Therefore, if the picture of an object that is far away, the lens must move towards the film.

The focal length cannot be changed because it is fixed for a lens. Nevertheless, in order to focus on an object, the image distance can be changed.

8 0
3 years ago
Martina has a sample of an unknown substance. She measures the substance. It’s mass is 13.5 grams, and it’s volume is 5 cm3 .Whi
Dominik [7]
Cm^3 is same as mL

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6 0
3 years ago
How much metabolic energy is required for a 68kg person to run at a speed of 15km/hr for 15min ?
irga5000 [103]
<span>What I have here is exactly the same problem, however, with the time changed to 19 mins:

metabolic energy = metabolic power*time = 1.150*19*60 = 1.311 kJ..corresponding to 1.311/4.186 = 313,2 Cal or kcal 

If we reasonably assume a metabolic eff.cy of 20%, it means we need to assume food for 1500 Cal approx.

Just plug the value t=15min to the equation and you will surely get the correct answer.

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8 0
3 years ago
2. A person began running due east and covered 15 kilometers in 2.0 hours. What is the average velocity of the person?
Angelina_Jolie [31]

Answer:

7.5 km/h (2.1 m/s) due east

Explanation:

The average velocity of the person is given by:

v=\frac{d}{t}

where

d is the displacement

t is the time taken

In this problem,

d = 15 km is the displacement

t = 2.0 h is the time elapsed

so the average velocity is

v=\frac{15 km}{2.0 h}=7.5 km/h

and the direction is the same as the displacement (east).

We can also convert the velocity into SI units (m/s). We have:

d = 15 km = 15,000 m

t = 2.0 h * 3600 s/h = 7200 s

v=\frac{15,000 m}{7200 s}=2.1 m/s

4 0
3 years ago
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Earth recycles water through select all that apply
Natasha2012 [34]

Answer:

evaporation to condensation to precipitation.

6 0
3 years ago
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