Solving Ball Clearing Fence: Does It Go Over?

  • Thread starter Thread starter apiwowar
  • Start date Start date
  • Tags Tags
    Ball
AI Thread Summary
The discussion revolves around a physics problem involving a batter hitting a ball at a height of 1.36 m and at a 45° angle, with a horizontal range of 112 m. The initial velocity was calculated to be 33.13 m/s, with its components determined as Vx = 23.43 m/s and Vy = 23.43 m/s. The time taken for the ball to reach 102 m was found to be 4.35 seconds, leading to a calculated height of 9.2 m at that point. However, there was confusion regarding the ball's clearance over a 7.65 m fence, as the expected height above the fence was incorrectly assessed. The problem references Halliday's "Fundamentals of Physics," indicating it is a standard physics exercise.
apiwowar
Messages
94
Reaction score
0
A batter hits a pitched ball when the center of the ball is 1.36 m above the ground.The ball leaves the bat at an angle of 45° with the ground. With that launch, the ball should have a horizontal range (returning to the launch level) of 112 m. (a) Does the ball clear a 7.65-m-high fence that is 102 m horizontally from the launch point? (b) At the fence, what is the distance between the fence top and the ball center?

so i solved for the initial velocity which is 33.13m/s
the i broke it up into its x and y components
Vx=23.43 m/s
Vy = 23.43 m/s

since the range is 112m i found the time that it takes for the ball to go 112m

t= x/Vx = 112m/23.43m/s

i then found the time it takes to 102 m using the same method and got 4.35s

so to find the height of the ball i did x=(23.43)(4.35)+1/2(9.8)(4.35)^2 = 9.2m

so i thought that it would be 2.91m above the fence but that's wrong.
where did i go wrong/?
 
Physics news on Phys.org
Did you consider the initial height of the ball?
 
yes

to figure out the distance between the ball and the fence

i did (9.2+1.36)-7.65
 
Your work looks good to me. What book is this from?
 
halliday, fundamentals of physics 9e
its a wiley plus problem
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top