1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
iren2701 [21]
3 years ago
7

The mass of a regulation tennis ball is 57 g. The ball is in contact with the tennis racket for 30 ms. The ball was served at 73

.14 m/s. If the opponent returned the serve with a speed of 55 m/s, what force did he exert on the ball, assuming only horizontal motion?
Physics
1 answer:
yaroslaw [1]3 years ago
8 0

Answer:

Correct answer:  F₂ = 104.5 N

Explanation:

Given:

m = 57 g = 57 · 10⁻³ kg

Δt = 30 ms = 30 · 10 ⁻³ seconds

V₁ = 73.14 m/s   service speed

V₂ = 55 m/s  returned speed

M = m · V  Momentum or Impulse

You forgot to indicate what time the ball contact when returning.

We will assume that the time is the same Δt = 30 ms = 30 10 ⁻³ seconds.

The formula for calculating force is according to Newton's second law is:

F = ΔM / Δt = m · ΔV / Δt

Force during service is:

F₁ = 57 · 10⁻³ · 73.14 / 30 · 10 ⁻³ = 138.97 N

F₁ = 138.97 N

Returned force:

F₂ =  57 · 10⁻³ · 55 / 30 · 10 ⁻³ = 104.5 N

F₂ =  104.5 N

God is with you!!!

You might be interested in
Five hundred joules of heat are added to a closed system. The initial internal energy of the system is 87 J, and the final inter
Aleonysh [2.5K]

We can solve the problem by using the first law of thermodynamics:

\Delta U= Q-W

where

\Delta U is the variation of internal energy of the system

Q is the heat added to the system

W is the work done by the system

In this problem, the variation of internal energy of the system is

\Delta U=U_f-U_i=134 J-87 J=47 J

While the heat added to the system is

Q=500 J

therefore, the work done by the system is

W=Q-\Delta U=500 J-47 J=453 J

5 0
3 years ago
Read 2 more answers
A student tests the acidity of nitric acid (HNO3) by dissolving a sample of HNO3 in a solution of liquid methane. He then uses a
DerKrebs [107]
Sorry I didn't see this before...
Okay, I see two major problems with this student's experiment:

1) Nitric acid Won't Dissolve in Methane
Nitric acid is what's called a mineral acid. That means it is inorganic (it doesn't contain carbon) and dissolves in water.
Methane is an organic molecule (it contains carbon). It literally cannot dissolve nitric acid. Here's why:
For nitric acid (HNO3) to dissolve into a solvent, that solvent must be polar. It must have a charge to pull the positively charged Hydrogen off of the Oxygen. Methane has no charge, since its carbon and hydrogens have nearly perfect covalent bonds. Thus it cannot dissolve nitric acid. There will be no solution. That leads to the next problem:

2) He's Not actually Measuring a Solution
He's picking up the pH of the pure nitric acid. Since it didn't dissolve, what's left isn't a solution—it's like mixing oil and water. He has groups of methane and groups of nitric acid. Since methane is perfectly neutral (neither acid nor base), the electronic instrument is only picking up the extremely acidic nitric acid. There's no point to what he's doing.

Does that help?
8 0
3 years ago
Read 2 more answers
How long does it take decaying organisms to transform into fossil fuels?
taurus [48]

Answer:

Millions or hundreds of million of years

Explanation:

It takes a very long time for decaying substances to form fossil fuels. It takes around millions or hundreds of million of years for the transformation to occur. This explains why they aren’t renewable.

Decayed plant materials usually form coal while decayed animal materials form crude oil.

7 0
3 years ago
A football player runs down a field with a speed of 8 m/s. How long will it take him to run 20m?
Shtirlitz [24]
To find the answer for this question, you simply need to divide 20 by 8, which is the speed he is traveling. 

20 / 8 = 2.5

The football player will run 20 yards in 2 1/2 seconds.
Hope that helped! =)
5 0
3 years ago
Read 2 more answers
Hawks and gannets soar above the ground and, when they spot prey, they fold their wings and essentially drop like a stone. They
denis-greek [22]

Answer:

  v = 54.2 m / s

Explanation:

Let's use energy conservation for this problem.

Starting point Higher

         Em₀ = U = m g h

Final point. Lower

        Em_{f} = K = ½ m v²

        Em₀ = Em_{f}

        m g h = ½ m v²

         v² = 2gh

         v = √ 2gh

Let's calculate

         v = √ (2 9.8 150)

         v = 54.2 m / s

3 0
2 years ago
Other questions:
  • A piano has a mass of 185 kg, and the coefficient of friction between it and the floor is 0.39. What is the maximum force of fri
    8·2 answers
  • This is the movement of soil, mud and rock due to the downward movement of wind, water or ice.
    11·2 answers
  • Tectonic plates are large segments of the Earth's crust that move slowly. Suppose that one such plate has an average speed of 4.
    14·1 answer
  • 3. A model rocket is launched straight upward at 58.8 m/s.
    11·1 answer
  • The force is the sum of all the forces that act upon an object
    9·1 answer
  • 4 points
    10·1 answer
  • A barbell is 1.5 m long. Three weights, each of mass 20 kg, are hung on the left and two weights of the same mass, on the right.
    8·1 answer
  • How would you design an experiment to condition a rabbit to salivate to the ringing of a cell phone?​
    11·1 answer
  • Please help. This question is urgent.​
    15·1 answer
  • HOW MANY SECONDS ARE THERE IN 3 MONTHS OF MARCH​
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!