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
katen-ka-za [31]
3 years ago
11

A ball is dropped from rest at point O. After falling for some time, it passes by a window of height 3.3 m and it does so in 0.2

7 s. The ball accelerates all the way down; let vA be its speed as it passes the window’s top A and vB its speed as it passes the window’s bottom B. Calculate the speed vA at which the ball passes the window’s top.
Physics
1 answer:
stiv31 [10]3 years ago
7 0

Answer:

Speed at which the ball passes the window’s top = 10.89 m/s

Explanation:

Height of window = 3.3 m

Time took to cover window = 0.27 s

Initial velocity, u = 0m/s

We have equation of motion s = ut + 0.5at²

For the top of window (position A)

                     s_A=0\times t_A+0.5\times 9.81t_A^2\\\\s_A=4.905t_A^2

For the bottom of window (position B)

                     s_B=0\times t_B+0.5\times 9.81t_B^2\\\\s_A=4.905t_B^2

\texttt{Height of window=}s_B-s_A=3.3\\\\4.905t_B^2-4.905t_A^2=3.3\\\\t_B^2-t_A^2=0.673

We also have

                 t_B-t_A=0.27

Solving

         t_B=0.27+t_A\\\\(0.27+t_A)^2-t_A^2=0.673\\\\t_A^2+0.54t_A+0.0729-t_A^2=0.673\\\\t_A=1.11s\\\\t_B=0.27+1.11=1.38s

So after 1.11 seconds ball reaches at top of window,

       We have equation of motion v = u + at

                                     v_A=0+9.81\times 1.11=10.89m/s

Speed at which the ball passes the window’s top = 10.89 m/s                

You might be interested in
A block weighing 30kg is moved at a constant speed over a horizontal surface by a force of 100 N applied parallel
DENIUS [597]
30-100=70^3•É+ 30 =3^E
5 0
3 years ago
If the cold temperature reservoir of a Carnot engine is held at a constant 306 K, what temperature should the hot reservoir be k
Paraphin [41]
Efficiency η of a Carnot engine is defined to be: 
<span>η = 1 - Tc / Th = (Th - Tc) / Th </span>
<span>where </span>
<span>Tc is the absolute temperature of the cold reservoir, and </span>
<span>Th is the absolute temperature of the hot reservoir. </span>

<span>In this case, given is η=22% and Th - Tc = 75K </span>
<span>Notice that although temperature difference is given in °C it has same numerical value in Kelvins because magnitude of the degree Celsius is exactly equal to that of the Kelvin (the difference between two scales is only in their starting points). </span>

<span>Th = (Th - Tc) / η </span>
<span>Th = 75 / 0.22 = 341 K (rounded to closest number) </span>
<span>Tc = Th - 75 = 266 K </span>

<span>Lower temperature is Tc = 266 K </span>
<span>Higher temperature is Th = 341 K</span>
6 0
3 years ago
A car with four passengers will have a shorter braking distance than a car with one braking distance. True or false. Why?
Valentin [98]

<u>Answer:</u>

The given statement is a True statement

<u>Explanation:</u>

All cars and trucks have load capacities marked on the jamb of the driver's door, as well as the owner's manual. This is very significant for braking distance.

A heavier object will require much more braking force and distance to stop, due to New ton's law of motion. “ An object in motion will tend to stay in motion “ .A heavy object will remain in motion longer and require much more force to stop. Four wheel disc brakes are great compared to front disc and rear drum configuration, in dissipating heat, and stopping more efficiently.

6 0
3 years ago
Formula for the distance (d) is given by d = rate*time. For example if you are traveling at 60 mph for 3 hours the distance trav
babunello [35]

Explanation:

Distance covered by the particle is given by:

Distance (d) = rate (v) × time (t)                

Speed of Mary, v₁ = 50 mph

Speed of Jim, v₂ = 60 mph

It is assumed that, Mary and Jim leave at the same time. After one hour, Jim is 10 miles ahead.

Distance travelled by Jim, d₁ = (60t + 10)

Distance travelled by Mary, d₂ = 50t

The distance between Mary and Jim is greater than or equal to 100 miles.

60t+10-50t\ge100

10t\ge90

t\ge9\ h

So, Jim takes is 9 hours more than Mary to cover same distance. Hence, this is the required solution.

7 0
3 years ago
You are in a car moving forward at 12 m/s. You throw a ball in the direction the car is moving. From your point of view, what do
4vir4ik [10]

Answer: it goes the same speed as the car

Explanation:

3 0
3 years ago
Other questions:
  • 1. Identify the quantity through the use of fundamental dimensions. nRT where: n = amount [mol] R = ideal gas constant [atm L/(m
    5·1 answer
  • Winston stands on the edge of a building's flat roof, 12 m above the ground, and throws a 147.0-g baseball straight down. the ba
    6·1 answer
  • How did anchient greeks spend there free time??
    11·1 answer
  • A water tower is idealized as a mass M on top of a uniform and massless beam. The bottom end of the beam is fixed to the ground.
    10·1 answer
  • Geosynchronous satellites orbit the Earth at a distance of 42 000 km from the Earth's center. Their angular speed at this height
    13·1 answer
  • A swimmer bounces straight up from a diving board and falls feet first into a pool. She starts with a velocity of 4.00 m/s, and
    12·1 answer
  • Atomic bombs send out a shock wave when they are detonated. This occurs because the bomb's detonation superheats the air particl
    5·2 answers
  • the rapid movement of gas molecules can be explained because gasses have size particles and exert attraction for other gas parti
    13·1 answer
  • Which object has unbalanced forces acting on it
    11·1 answer
  • A baseball on the Moon and an identical baseball on the Earth are thrown vertically upward with the same initial velocity of 12
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!