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
garri49 [273]
3 years ago
10

A baseball is hit that just goes over a wall that is 45.4m high. If the baseball is traveling at 46.2 m/s at an angle of 32.7° b

elow the horizontal when it crosses the wall, and if the ball was initially hit by the batter when the ball was 1m above the ground, a. What was the ball’s initial velocity (state speed and angle)
Physics
1 answer:
mario62 [17]3 years ago
5 0

Answer:

54.9 m/s at 44.9 degrees

Explanation:

If the ball has a total velocity of 46.2 m/s, at an angle of -32.7 degrees, we can decompose its speed into its horizontal and vertical components.

Vx = V * cos(a) = 46.2 * cos(-32.7) = 38.9 m/s

Vy = V * sin(a) = 46.2 * sin(-32.7) = -25 m/s

SInce there is no force on the horizontal direction (omitting air drag), we can assume constant horizontal speed.

Since a ball thrown is at free fall, only affected by gravity (omitting air drag), we can say it is affected by constant acceleration, therefore we can use

Y(t) = Y0 + Vy0 *t + 1/2 * a * t^2

We consider t=0 as the moment when the ball was hit, so in this case Y0 = 1 m

If we take the first derivative of the equation of position, we get the equation for speed

V(t) = Vy0 + a * t

We know that being t2 the moment the ball goes over the wall

V(t2) = -25 m/s

Y(t2) = 45.4 m

So:

45.4 = 1 + Vy0 * t2 + 1/2 * a * t2^2

-25 = Vy0 + a * t2

Then:

Vy0 = -25 - a * t2

So:

45.4 = 1 + (-25 - a * t2) * t2 + 1/2 * a * t2^2

0 = -44.4 - 25 * t2 - 1/2 * a * t2^2

a = -9.81 m/s^2

0 = -44.4 - 25 * t2 + 4.9 * t2^2

Solving this quadratic equation we get:

t1 = -1.39 s

t2 = 6.5 s

Since we are looking for a positive value we disregard t1.

Now we can obtain Vy0:

Vy0 = -25 + 9.81 * 6.5 = 38.76 m/s

Since horizontal speed is constant Vx0 = 38.9 m/s

By Pythagoras theorem we obtain the value of the initial speed:

V0 = \sqrt{Vx0^2 + Vy0^2} = \sqrt{38.9^2 + 38.76^2} = 54.9 m/s

The angle is in the the first quadrant because both comonents ate positive, so: 0 < a < 90

a = atan(Vy0/Vx0) = 44.9 degrees

You might be interested in
A car travels West at 35 mph for a time period of 2.5 hours and then travels West at 55 mph for an additional time of 4.0 hours.
OlgaM077 [116]

The total distance travelled is 307.5 miles.

<h3>What is the distance covered?</h3>

We know that the distance covered can be obtained from the formula from speed since the motion all took place in the same direction.

Speed = distance/time

distance = speed * time

In the first case;

Distance =  35 mph  *  2.5 hours = 87.5 miles

In the second case;

Distance =  55 mph * 4.0 hours = 220 miles

Total distance = 87.5 miles + 220 miles = 307.5 miles

Hence the total distance travelled is 307.5 miles.

Learn more about total distance:brainly.com/question/20330990

#SPJ1

7 0
1 year ago
A ball rolls down a ramp for 15 seconds. If the initial velocity of the ball was 0.8m/s and the final velocity was 7m/s, what wa
iren [92.7K]
Acceleration = (change in speed) / (time for the change)

Change in speed = (ending speed) - (starting speed)

                            =  (7.0 m/s)  -  (0.8 m/s)  =  6.2 m/s

Time for the change  =  15 seconds

Acceleration  =  (6.2 m/s) / (15 sec)

                      =   (6.2/15)  m/s²

                      =     0.413 m/s²  
6 0
3 years ago
Which of the following situations would violate the second law of
Sonja [21]

Answer:

c

Explanation:i don’t know

6 0
3 years ago
What Does This Poem Mean?
Ann [662]
Nakakakak skskskksksksks
7 0
2 years ago
Describe the climate and name the climate zone at alaska; portland, oregon; and key west, florida.
Tpy6a [65]
Alaska-                   Subartic Climate 
Portland, Oregon-  Marine West Coast Climate
Key West, Florida- Tropical Savannah Climate
3 0
2 years ago
Other questions:
  • A toaster oven uses67,500 joules of energy in 45 seconds to toast a piece of bread what is the power of the oven
    12·1 answer
  • (HELP!!! 30 pts if answered right. )What formula gives the strength of an electric field, E, at a distance from a known source c
    11·1 answer
  • A spring scale hung from the ceiling stretches by 6.1 cm when a 2.0 kg mass is hung from it. The 2.0 kg mass is removed and repl
    13·1 answer
  • How much physical activity should an adult have each week?
    11·1 answer
  • Will an object with a density of 1.05 g/ml float or sink in water? Explain
    14·1 answer
  • At the instant its angular displacement is 0.32 rad, the angular acceleration of a physical pendulum is -630 rad/s2. What is its
    7·2 answers
  • A 3000-kg spaceship is moving away from a space station at a constant speed of 3 m/s. The astronaut in the spaceship decides to
    9·1 answer
  • a woman is swimming across a cold lake. her body temperature is 98 degrees fahrenheit , and the lake water is at 60 degrees fahr
    9·1 answer
  • Using my raw survival instincts, I am trying to catch a trout from a stream with my bare hands. Despite my exceptional reflexes
    14·2 answers
  • A polar jet is a belt of winds about 600 miles wide, flowing as fast as _________
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!