Problem 4-54 - Projectile - Part 2 - C

A child throws a snowball straight toward a tree with a horizontal velocity of \(18\; m/s\). The tree is \(9.0\; m\) away and the snowball starts from a height of \(1.5\; m\) above the ground.

(a) How long will the snowball take to reach the tree?
(b) At what height above the ground will the snowball hit the tree?
(c) What is the snowball's velocity as it hits the tree?
[Ans. (a) \(0.50\; s\)   (b) \(0.3\; m\)   (c) \(19\; m/s\; 15^\circ\) down from the horizontal]

Accumulated Solution

Diagram of the accumulated solution.


The other equally good one is (A). We will use this one in our solution but when it is finished you would be well to repeat it with the choice (A) for the coordinate system. You must, of course get the same answers.

Here is your choice with all the data added (h is what we are asked to find).

Diagram of coordinate system.

In this problem the acceleration is:

(A)  \(9.8\; m/s^2 \text{up}\; (+y)\)

(B)  \(9.8\; m/s^2 \; \text {down} \;(-y)\)

(C)  \(9.8\; m/s^2 \; \text{to the right} \;(+x)\)

(D)  \(9.8\; m/s^2\; \text{to the left}\; (-x)\)