# Olympic problem from kinematics

#### KrolKuabV

Summary: Olympic problem from kinematics

Hello,
could anyone help me with the following problem? I don't quite get how exactly does it work.

After being kicked by a footballer, a ball started to fly straight towards the goal at velocity v = 25m/s making an angle α = arccos 0.8 with the horizontal. Due to side wind blowing at u = 10 m/s perpendicular the initial velocity of the ball, the ball had deviated from its initial course by s = 2 m by the time it reached the plane of the goal. Find the time that it took the ball to reach the plane of the goal, if the goal was situated at distance L = 32 m from the footballer.

This problem is from this PDF https://www.ioc.ee/~kalda/ipho/kin_ENG.pdf . Thanks for any help!

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#### PeroK

Homework Helper
Gold Member
2018 Award
As per PF rules you need to show your best attempt.

Hint: if the wind affects the ball in the transverse direction, what can you say about motion in the other directions?

#### haruspex

Homework Helper
Gold Member
2018 Award
The problem requires you to make a completely invalid assumption. (Grrr!)
Pretend instead that the side wind velocity given is relative to the velocity of the ball. Even then, it doesn’t quite work.

"Olympic problem from kinematics"

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