How High Was the Ball Thrown From the Building?

  • Thread starter Thread starter GlobalDuty
  • Start date Start date
  • Tags Tags
    Ball Building
Click For Summary
SUMMARY

The problem involves calculating the height from which a ball was thrown from a building, given an initial velocity of 8.70 m/s at an angle of 22.0° below the horizontal and a time of flight of 5.00 seconds. The initial vertical velocity must be calculated using trigonometric functions, specifically by applying the sine function to the angle. The correct formula to determine the height is yf - yi = 1/2(Vy + Vi)t, where Vy is the vertical component of the initial velocity. The correct height calculation yields a value of 166 meters after properly accounting for the angle of projection.

PREREQUISITES
  • Understanding of projectile motion principles
  • Basic knowledge of trigonometry, specifically sine and cosine functions
  • Familiarity with kinematic equations in physics
  • Ability to resolve vectors into components
NEXT STEPS
  • Learn how to resolve vectors into horizontal and vertical components using trigonometric functions
  • Study kinematic equations for projectile motion in detail
  • Explore additional resources on projectile motion formulas available on platforms like Wikipedia
  • Practice solving similar problems involving angles and initial velocities in projectile motion
USEFUL FOR

Students studying physics, educators teaching kinematics, and anyone interested in mastering projectile motion calculations.

GlobalDuty
Messages
26
Reaction score
0

Homework Statement


A ball is tossed from an upper-story window of a building. The ball is given an initial velocity of 8.70 m/s at an angle of 22.0° below the horizontal. It strikes the ground 5.00 s later.
Find the height from which the ball was thrown.


The Attempt at a Solution


i found final Velocity first: -8.70 + (-9.80)(5) and i got -57.7
then i used this formula yf-yi = 1/2(Vy+Vi)t 1/2(-57.7 + -8.70)5
to get 166 for the height, but it is wrong.
 
Physics news on Phys.org
The problem is that you took the entire initial velocity to be in the vertical direction, but the ball was thrown at an angle so in reality, part of that velocty is in the horizontal direction. You need to use the initial angle given and solve for the initial velocty in the y direction, and that's the velocity that will change due to gravity.
 
thank you, that helped
 
Try using some of the extra forumlas given for projectile motion, you can find them on wikipedia ect. they help a lot, plus they're easier to use then 2D motion
 

Similar threads

Replies
7
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 31 ·
2
Replies
31
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K
Replies
3
Views
2K
Replies
8
Views
4K
Replies
14
Views
3K
  • · Replies 5 ·
Replies
5
Views
14K