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
Drupady [299]
3 years ago
5

A baseball player friend of yours wants to determine his pitching speed. You have him stand on a ledge and throw the ball horizo

ntally from an elevation 5.0 mm above the ground. The ball lands 20 mm away. What is his pitching speed?
Physics
1 answer:
Alla [95]3 years ago
4 0

Answer:

v_{ox}= 19.6\ m/s

Explanation:

Data provided in the question:

Height above the ground, H= 5.0m

Range of the ball, R= 20 m

Initial horizontal velocity = v_{ox}

Initial vertical velocity= v_{oy}  (Since ball was thrown horizontally only)

Acceleration acting horizontally, a_x = 0 m/s²  [ Since no acceleration acts horizontally) ]

Vertical Acceleration, a_y = 9.8 m/s² (Since only gravity acts on it)

Let 't' be the time taken to reach ground

Therefore, using equations of motion, we have

H= v_{oy}t+\frac{1}{2}a_yt^2

5= (0)t+\frac{1}{2}(9.8)t^2

t= \frac{10}{9.8}=1.02 s

Then using Equations of motion for horizontal motion,

R= v_{ox}t+\frac{1}{2}a_xt^2

20= v_{ox}(1.02)+\frac{1}{2}(0)(1.02)^2

v_{ox}= 19.6\ m/s

You might be interested in
A lab cart with a mass of 15 kg is moving with constant velocity, v, along a straight horizontal track. A student drops a 2 kg m
lbvjy [14]

The equation 15v_{i} + 2*0 = (15 + 2)v_{f} (option 3) represents the horizontal momentum of a 15 kg lab cart moving with a constant velocity, v, and that continues moving after a 2 kg object is dropped into it.  

The horizontal momentum is given by:

p_{i} = p_{f}

m_{1}v_{1}_{i} + m_{2}v_{2}_{i} = m_{1}v_{1}_{f} + m_{2}v_{2}_{f}

Where:

  • m₁: is the mass of the lab cart = 15 kg
  • m₂: is the <em>mass </em>of the object dropped = 2 kg
  • v_{1}_{i}: is the initial velocity of the<em> lab cart </em>
  • v_{2}_{i}: is the <em>initial velocit</em>y of the <em>object </em>= 0 (it is dropped)
  • v_{1}_{f}: is the final velocity of the<em> lab cart </em>
  • v_{2}_{f}: is the <em>final velocity</em> of the <em>object </em>

Then, the horizontal momentum is:

15v_{1}_{i} + 2*0 = 15v_{1}_{f} + 2v_{2}_{f}

When the object is dropped into the lab cart, the final velocity of the lab cart and the object <u>will be the same</u>, so:

15v_{1}_{i} + 2*0 = v_{f}(15 + 2)

Therefore, the equation 15v_{i} + 2*0 = (15 + 2)v_{f} represents the horizontal momentum (option 3).

Learn more about linear momentum here:

  • brainly.com/question/2141713?referrer=searchResults
  • brainly.com/question/2400186?referrer=searchResults

I hope it helps you!            

4 0
3 years ago
Which equation is used to determine the density of a substance?
Mademuasel [1]
The answer is D=M/V hope it helps!!
3 0
3 years ago
Read 2 more answers
Work done by a gravitational force by lowering the bucket into the well is
katovenus [111]

Answer:

when we lower a bucket into a well to fetch water, the work done by gravity is positive since force and displacement are in the same direction.

Explanation:

3 0
3 years ago
A car speeding down the highway honks its horn, which has a frequency 392 Hz, but a resting bystander hears the frequency 440 Hz
Natali [406]

Answer:

37.42 m/s

Explanation:

We know that apparent frequency, \bar f is given by

\bar f=f\frac {V}{V-V_s} where f is the given frequency in this case 392, V is the speed of sound in air which is given as 343 and V_s is the speed of car which is unknown, \bar f is given as 440 Hz

440=392\times \frac {343}{343-V_s}\\343-V_s=392\times \frac {343}{440}=305.5818182\\V_s=343-305.5818182=37.41818182\approx 37.42 m/s

8 0
3 years ago
By what factor must the amplitude of a sound wave be decreased in order to decrease the intensity by a factor of 3?
s344n2d4d5 [400]

Answer:

Amplitude is decreased by a factor of \sqrt3 if intensity is decreased by a factor of 3.

Explanation:

Intensity of a sound wave is directly proportional to the square of its amplitude.

Therefore, if intensity is I and amplitude is A, then

I=kA^2, where, k is constant of proportionality.

Now, if intensity of sound wave is decreased by a factor of 3. So,

New intensity is, I_{new}=\frac{I}{3}

I_{new}=kA_{new}^2\\\frac{I}{3}=kA_{new}^2

Plug in kA^2 for I. This gives,

\frac{kA^2}{3}=kA_{new}^2\\A_{new}^2=\frac{A^2}{3}\\A_{new}=\sqrt{\frac{A^2}{3}}=\frac{A}{\sqrt{3}}

Therefore, amplitude is decreased by a factor of \sqrt3.

4 0
3 years ago
Other questions:
  • What is the kinetic energy of a 50-kg child running to catch the school bus at
    5·2 answers
  • Which description correctly summarizes how an electric motor causes an axle to turn?
    6·1 answer
  • find the resistance of a resistor connected to a 3v voltmeter and a 3A ammeter, resistance box along with cells of EMF 3V​
    11·1 answer
  • The picture is there. Please help
    14·1 answer
  • Reto: Aníbal desea construir una carpa de base hexagonal de 1,40 m de altura. El vértice de la base es de 0,80m y la longitud de
    6·1 answer
  • How long must a flute be in order to have a fundamental frequency of 262 Hz (this frequency corresponds to middle C on the evenl
    9·1 answer
  • The comparison between work output and work input is
    5·2 answers
  • The energy of a photon is 9.7eV what is the wavelength
    14·1 answer
  • Propane (c3h8), a common fuel, reacts with oxygen to form carbon dioxide and water according to the equation below. c3h8 5o2 → 3
    8·1 answer
  • A current of 0. 82 a flows through a light bulb. how much charge passes through the light bulb during 94 s?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!