What is the speed of the pitch?

  • Thread starter Thread starter SirajK
  • Start date Start date
  • Tags Tags
    Pitch Speed
Click For Summary
SUMMARY

The discussion centers on calculating the pitching speed of a baseball thrown horizontally from a height of 4.0 meters, landing 25 meters away. Participants utilize kinematic equations to derive the time of flight based on vertical motion, specifically using the equation y = (1/2)(9.81)t² + 4. The horizontal distance is then expressed as x = vt, where v represents the horizontal velocity. The conversation highlights the importance of correctly interpreting the distance as the horizontal component and addresses the impact of air resistance on the calculation.

PREREQUISITES
  • Understanding of kinematic equations in physics
  • Knowledge of projectile motion principles
  • Familiarity with basic algebra for solving equations
  • Awareness of the effects of air resistance on projectile motion
NEXT STEPS
  • Study the derivation of kinematic equations for projectile motion
  • Learn how to calculate the effects of air resistance on projectile trajectories
  • Explore advanced topics in physics such as vector decomposition in motion
  • Investigate real-world applications of projectile motion in sports science
USEFUL FOR

Physics students, educators, and sports scientists interested in understanding the dynamics of projectile motion and its applications in sports like baseball.

SirajK
Messages
1
Reaction score
0

Homework Statement


A baseball player friend of yours wants to determine his pitching speed. You have him stand on a ledge and throw horizontally from an elevation 4.0 m above the ground. The ball lands 25 m away. What is his pitching speed?

Homework Equations


Kinematics Equations:
http://www.google.ca/imgres?imgurl=...AAzT5KPLeL30gHW3JDFBw&ved=0CD8Q9QEwAg&dur=255
 
Physics news on Phys.org
sjb-2812 said:
Are you sure R should be 25 here?

I'm never sure, 8^)

What do you think it should be?
 
Your "kinematic equations" refer to the vertical motion only. You say the ball is thrown horizontally so the initial vertical component is 0. The height of the ball, at time t, is y= (1/2)(9.81)t^2+ 4. Set that equal to 0 (the ball hits the ground) and solve for t to find when the ball hits the ground.

Taking "v" as the horizontal component of velocity, the distance the ball traveled, in time t, is given by x= vt. Put x= 25, t equal to the time you solved for above, and solve for v.

That, of course, is ignoring air resistance- which is fairly large for a baseball.
 
Spinnor said:
I'm never sure, 8^)

What do you think it should be?

Maybe it's the way the question is worded, but the figure of 25 to me seems to be the hypotenuse, rather than the adjacent for the triangle?


HallsofIvy said:
Your "kinematic equations" refer to the vertical motion only. You say the ball is thrown horizontally so the initial vertical component is 0. The height of the ball, at time t, is y= (1/2)(9.81)t^2+ 4. Set that equal to 0 (the ball hits the ground) and solve for t to find when the ball hits the ground.

Taking "v" as the horizontal component of velocity, the distance the ball traveled, in time t, is given by x= vt. Put x= 25, t equal to the time you solved for above, and solve for v.

That, of course, is ignoring air resistance- which is fairly large for a baseball.

Check your signs here :)
 
You wrote,

"Maybe it's the way the question is worded, but the figure of 25 to me seems to be the hypotenuse, rather than the adjacent for the triangle?"

On second reading I agree, thanks for the correction.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 1 ·
Replies
1
Views
8K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
2
Views
2K
Replies
3
Views
17K
  • · Replies 9 ·
Replies
9
Views
4K
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
4K