Calculate Time Until Tree is Hit: 9m Away, 18m/s Velocity

AI Thread Summary
To calculate the time it takes for the ball to hit the tree, the horizontal distance of 9 meters and the constant horizontal velocity of 18 m/s can be used, yielding a time of 0.5 seconds. The vertical motion can be analyzed separately, starting from an initial height of 1.5 meters with no initial vertical velocity. Using the equation for vertical motion under gravity, the height at which the ball hits the tree can be determined. The final vertical velocity can also be calculated using kinematic equations. The discussion highlights the importance of separating horizontal and vertical motions in projectile problems.
newtonsmac
Messages
4
Reaction score
0

Homework Statement



- ball is thrown with a horizontal velocity of 18 m/s directly toward a tree
- person who threw the ball is 1.5 m above the ground and 9 m away from the tree

looking for time it takes to hit the tree, what height the ball hits the tree at, and the balls velocity when it does so.

Homework Equations



Well, we know the velocity of x which is 18 m/s, the initial y velocity which is zero, the distance between the ball and the tree which is 9m and the initial height of the ball which 1.5m.

To find time there are many formulas but they all have (delta)d of y, but u don't have d2 so i can't find it using any of those. After getting time i can the formulas to find the others.

The Attempt at a Solution

No idea. No formulas that have what i need.

Do i need to first find the y final velocity using a different formula??
 
Last edited:
Physics news on Phys.org
i would just use v=x/t to solve for time because there is no acceleration.
 
Thanks.

I forgot that vx stays constant.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top