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ICE Princess25 [194]
3 years ago
11

A 120-kg roller coaster cart is being tested on a new track, and a crash-test dummy is loaded into itThe roller coaster starts f

rom rest at point A which is 35 m above the ground. The cart is observed to roll down the track to point Bwhich is 10 m above the ground . In your own words, what physics ideas would you be able to use to predict how fast the cart is moving at point B? What calculations would you use, what things would you be measuring , and what physics principles or laws would you use to make this calculation ?
Physics
1 answer:
Black_prince [1.1K]3 years ago
7 0

Answer:

a) variation of the energy is equal to the work of the friction force

b) W = Em_{f} -Em₀ ,  c) he conservation of mechanical energy

Explanation:

a) In an analysis of this problem we can use the energy law, where at the moment the mechanical energy is started it is totally potential, and at the lowest point it is totally kinetic, we can suppose two possibilities, that the friction is zero and therefore by equalizing the energy we set the velocity at the lowest point.

 Another case is if the friction is different from zero and in this case the variation of the energy is equal to the work of the friction force, in value it will be lower than in the calculations.

b) the calluses that he would use are to hinder the worker's friction force and energy

          W = Em_{f} -Em₀

          N d = ½ m v² - m g (y₂-y₁)

          y₂-y₁ = 35 -10 = 25m

c) if there is no friction, the physical principle is the conservation of mechanical energy

 If there is friction, the principle is that the non-conservative work is equal to the variation of the energy

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Explanation:

The following data were obtained from the question:

Distance (d) = 147 miles

Time (t) = 2.47 hours.

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Speed (S) = Distance (d) / time (t)

S = d/t

With the above formula, we can obtain the speed of the girl as illustrated below:

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2 years ago
The tub of a washer goes into its spin-dry cycle, starting from rest and reaching an angular speed of 5.0 rev/s in 8.0 s. At thi
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Answer:

The total number of revolution is 50 rev.

Explanation:

Given that,

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Put the value into the formula

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\theta''=\theta+\theta'

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