# Solving Projectile Problems You might think 30 meters is the displacement in the x direction, but that's a vertical distance.This is not telling us anything about this horizontal distance.

You might think 30 meters is the displacement in the x direction, but that's a vertical distance.This is not telling us anything about this horizontal distance.So this person just ran horizontally straight off the cliff and then they start to gain velocity.

This vertical velocity is gonna be changing but this horizontal velocity is just gonna remain the same. In other words, this horizontal velocity started at five, the person's always gonna have five meters per second of horizontal velocity.

So this horizontal velocity is always gonna be five meters per second.

So if something is launched off of a cliff, let's say, in this straight horizontal direction with no vertical component to start with, then it's a horizontally launched projectile. I mean a boring example, it's just a ball rolling off of a table.

If you just roll the ball off of the table, then the velocity the ball has to start off with, if the table's flat and horizontal, the velocity of the ball initially would just be horizontal. Let's say this person is gonna cliff dive or base jump, and they're gonna be like "whoa, let's do this." We're gonna do this, they're pumped up.

So if you choose downward as negative, this has to be a negative displacement. Well, for a freely flying object we know that the acceleration vertically is always gonna be negative 9.8 meters per second squared, assuming downward is negative.

Now, here's the point where people get stumped, and here's the part where people make a mistake.We don't know how to find it but we want to know that we do want to find so I'm gonna write it there. We know that the, alright, now we're gonna use this 30.You might want to say that delta y is positive 30 but you would be wrong, and the reason is, this person fell downward 30 meters. They started at the top of the cliff, ended at the bottom of the cliff.So a lot of vertical velocity, this should keep getting bigger and bigger and bigger because gravity's influencing this vertical direction but not the horizontal direction. V initial in the x, I could have written i for initial, but I wrote zero for v naught in the x, it still means initial velocity is five meters per second.And we don't know anything else in the x direction.- [Instructor] Let's talk about how to handle a horizontally launched projectile problem.These, technically speaking, if you already know how to do projectile problems, there is nothing new, except that there's one aspect of these problems that people get stumped by all of the time.They want to say that the initial velocity in the y direction is five meters per second.I mean people are just dying to stick these five meters per second into here because that's the velocity that you were given. That's why this is called horizontally launched projectile motion, not vertically launched projectile motion. The initial velocity in the vertical direction here was zero, there was no initial vertical velocity.Maybe there's this nasty craggy cliff bottom here that you can't fall on.So how fast would I have to run in order to make it past that?

## Comments Solving Projectile Problems

• ###### Solving Projectile Motion Using Energy - Clutch Prep
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Video explaining Solving Projectile Motion Using Energy for Physics. This is one of many videos provided by Clutch Prep to prepare you to succeed in your…

• ###### Physics - Solving a projectile trajectory problem - Mathematica
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Begingroup\$ Your parametric plot is correct. FindRoot is solving the equation yt=0 for t, using the best guess of t=70 as a starting point. Once you've found the time at which the projectile hits the ground y=0 you can ask what it's x position was at that time as well.…

• ###### Projectile Motion Study Guide - Intuitor
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Projectile Motion. The key to all projectile motion problems is to treat them as two separate kinematics problems, one in the x-dimension and one in the y-dimension. Write equations until the number of equations matches the number of unknowns, then solve them simultaneously.…

• ###### Non-Horizontally Launched Projectiles – Problem-Solving
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And problems can often be simplified by the use of short procedures as the one above. However, not all problems can be solved with the above procedure. While steps 1, 2 and 3 above are critical to your success in solving non-horizontally launched projectile problems, there will always be a problem that doesn’t “fit the mold.”…

• ###### HP Prime Solving Projectile Motion with the Solve App
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HP Prime Solving Projectile Motion with the Solve App This blog entry is a demonstration using the Solve App to solve a variety of problems regarding projectile motion. Getting Started…

• ###### Strategies for Solving Problems - harvard.edu
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Possible solving problems which is inevitably an active task beyond the time you spend reading which is generally a more passive task. I have therefore included a very large number of problems/exercises in this book. However, if I’m going to throw all these problems at you, I should at least give you some general strategies for solving them.…

• ###### What's an easy and reliable way to solve confusing projectile motion.
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Background Did IBDP higher level physics, got 7 points and currently giving part-time physics tuition. Here is the answer to your question. In general, while answering projectile motion questions you should always list down the variables p.…

• ###### Horizontally Launched Projectiles – Problem-Solving
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Furthermore, for the special case of the first type of problem horizontally launched projectile problems, v iy = 0 m/s. Thus, any term with v iy in it will cancel out of the equation. The two sets of three equations above are the kinematic equations that will be used to solve projectile motion problems. Solving Projectile Problems…

• ###### Solving Problems with Vectors -
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Solving Problems with Vectors We can use vectors to solve many problems involving physical quantities such as velocity, speed, weight, work and so on. Velocity The velocity of moving object is modeled by a vector whose direction is the direction of motion and whose magnitude is the speed.…