Projectile launch at elevated height on angle

AI Thread Summary
A baseball player hits a home run with a ball leaving the bat at 45 m/s at a 36.9° angle, starting from 1 m above ground and clearing a fence at 11 m. The vertical and horizontal velocities were calculated as 27 m/s and 36 m/s, respectively. The time of flight was determined to be approximately 5.1 seconds. The total distance traveled by the ball was calculated to be 198 m, leading to the need for further calculations to find the distance to the fence. A suggestion was made to draw a diagram to simplify the problem-solving process.
rahrahrah1
Messages
8
Reaction score
0

Homework Statement



a baseball player hits a home run. The ball's velocity as it leaves the bat is 45m/s at an angle of 36.9° above the horizontal. At the point of impact with the bat, the ball is 1 m above ground level, and as it clears the fence it is back down to 11 m above ground level. How far from home plate is the fence at this point?

Homework Equations


quadratic formula
linear motion equations
basic sin and cos
v=d/t

The Attempt at a Solution



so I started with finding the Vv and the Vh velocties
vh= 45cos6.9= 36.0
Vv= 45sin36.9 = 27.0

then I organized the information I had into two separate headings
Vv
v1: 27 m/s
v2:*27.4m/s
a: -9.8m/s
t:*5.5
d: -1m

and Vh
vave: 36m/s
t:*5.5
d:*198m

*I found the time using the quadratic formula and came up with 5.5 seconds
* I calculated the total distance the ball traveled using the formula d = v×t and got 198 m
* calulated the v2 for the Vv to be 27.4 m/s using linear motion equation
I'm thinking i need a colum for the fence distance now, however, this part is slightly iffy.

Vh for fence
vave:
t:T
d: 198-D

Vv for fence
v1:
v2:
a:-9.8m/s
t:T
d: -11m

At this point I've hit a dead end.
 
Physics news on Phys.org
The question states the ball is at 11m above the ground

So displacement is 10m.
Calculate your time again.(its not right)

After you have time
You will need to multiply it by v(h)*t to get d.(as you already did)

Thats all.thats your answer

I don't understand what (and why)you are doing in the latter part of your post.
 
Hmm, I always manage to overcomplicate an easy question. thanks, I calculated my time to be 5.1 secs.
 
Your answer appears correct.
 
rahrahrah1 said:
Hmm, I always manage to overcomplicate an easy question. thanks, I calculated my time to be 5.1 secs.


Always draw a diagram :-)
That shortens the problem in so many ways.

Your time is correct :-)
Now all that is left is to find the distance.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
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