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Darina [25.2K]
3 years ago
7

Sally and Ramona were competing in a four-lap, one-mile foot race. Sally’s style was to run at a constant rate of 12 mph. Ramona

decided to run her first three laps at 11 mph, and save a ‘kick’ in order to run a 16 mph pace for the fourth and final lap. Who wins the race, and by how many minutes or seconds?
Physics
1 answer:
svetoff [14.1K]3 years ago
7 0

Sally wins the race by 0.03 min

Explanation:

To find time = distance / velocity

Sally;

1 mile / 12 mph

= ¹/12 hrs * 60

= 5 min

Ramona;

³/4 mile ÷ 11 mph  +  ¹/4 mile ÷ 16 mph

= ³/44 hrs + ¹/64 hrs

= 4.09 min + 0.94 min

= 5.03 min

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Assuming the friction between the skaters and the ice is  negligible, the magnitude of Porsha's acceleration is 2.8m/s².

Missing part of the question: determine the magnitude of Porsha's acceleration.

Given the data in the question;

  • Mass of Porsha; m_{porsha} = 60kg
  • Mass of Zorn; m_{zorn} = 40kg
  • Force of Porsha push; F_{porsha} = 168N

Magnitude of Porsha's acceleration; a = \ ?

To determine the magnitude of Porsha's acceleration, we use Newton's second laws of motion:

F = m*a

Where m is the mass of the object and a is the acceleration.

We substitute the mass of Porsha and the force he used into the equation

168N = 60kg * a\\\\a = \frac{168kg.m/s^2}{60kg}\\\\a = 2.8m/s^2

Therefore, assuming the friction between the skaters and the ice is  negligible, the magnitude of Porsha's acceleration is 2.8m/s².

Learn more: brainly.com/question/25125444

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3 years ago
In a real machine, the work output is always less than the work input.<br> a. True<br> b. False
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All matter has electrical and magnetic properties because the atoms that make up matter are held together by electromagnetic for
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Answer:

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Explanation:

Charge is a fundamental property of all matter. All matter has electrical and magnetic properties because the atoms that make up matter are held together by electromagnetic forces.

These charges are usually positive and negative charges. When these charges which make up an atom (positive and negative) are equal, the atom is said to be electrically neutral. When positive charge is greater than negative charge, the atom is said to positively charged. Also, if the number of negative charges are more in an atom, the atom is said to be negatively charged.

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3 years ago
A circular-motion addict of mass 80 kg rides a Ferris wheel around in a vertical circle of radius 10 m at a constant speed of 6.
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Answer with Explanation:

We are given that

Mass=80 kg

Radius,r=10 m

Speed,v=6.1 m/s

a.Time period,T=\frac{2\pi r}{v}=\frac{2\pi\times 10}{6.1}=10.3 s

b.F_N=mg-\frac{mv^2}{r}

Substitute the values

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Define SI unit of measurement.​
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