A Ball Is Thrown With A Velocity U= 40 M/s At An Angle 60 Degrees With The Horizontal Towards A Wall Slanting At An Angle 45 Degrees With The Horizontal. At What Point Will The Ball Hit The Wall?


4 Answers

Hello Boss Profile
Hello Boss answered
It won't hit the wall, I can't throw that hard. Beside all that, I am not a mathematician.
thanked the writer.
Vin Ravun
Vin Ravun commented
Lolz. But it will hit the wall i'm sure.
Ady Mat
Ady Mat commented
Lol Your answers and comments are often interesting and make me laugh a lot.
Hello Boss
Hello Boss commented
I try to be entertaining as much as possible. But, watch out when I'm off my Meds, then I'm a Holy terror.
Oddman Profile
Oddman answered
The vertical height of the ball at time t will be
  hb = -16t^2 + 40Sin[60°]t
The horizontal displacement of the ball at time t will be
  d = 40Cos[60°]t
This horizontal displacement is also the difference between the height of the wall and 20 m.
  Hw = 20 - 40Cos[60°]t
The ball will hit the wall when the ball height hb is equal to the wall height hw.
  -16t^2 + 40Sin[60°]t = 20 - 40Cos[60°]t
  0 = 20 - t(20+20√3) + 16t^2
The solution to this can be found using the quadratic formula. It will be something like
  t = (5(1+√3)-√(20+50√3))/8 ≈ 0.416925
The (x, y) coordinates of the point of contact are (d, hw) = (8.3385, 11.6615) meters.
thanked the writer.
Vin Ravun
Vin Ravun commented
Thank you,but i didn't understand why you wrote -16t^2.Could you please explain?
Oddman commented
An object experiencing acceleration "a" moves distance (1/2)*a*t^2 in time "t". Acceleration due to gravity is approximated in these problems by 32 ft/sec/sec in the downward direction. Half that is -16 ft/s^2. Of course, now that I write that, I see that I should have used the metric version of the gravitational constant. The term should be -4.9t^2. The method is right, but the numbers need correction. Sorry about that.
Oddman commented
Revised impact point coordinates are (7.578, 12.422) meters from the origin. Impact is in about 0.3789 seconds.
luth dela cruz Profile
luth dela cruz answered
At 75 % angle of depression...
Jillian Peppe Profile
Jillian Peppe answered
To determine at what point the ball hits the wall you would need the distance to travel of the ball and also need the calculation of the deviation of the flight of the ball and size, shape and weight of the ball.
thanked the writer.
Vin Ravun
Vin Ravun commented
The distance of travel can be calculated.Also the velocity,displacement are all independent of mass.The ball in this problem is just a particle (a point mass).

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