Projectile Motion - Engineering Dynamics

introduction and explanation of the projectile motion problem

[@ltmillerII]

wow. a much easier verison of projectile motion than given by my physics teacher. thanks!

[@ALV57]

Had a good hour lecture with examples and was completely lost. Watched the first 7 minutes of this video and now I'm ashamed at how easy this is. Awesome presentation! My instructor is not very visual and has an extremely thick accent so I don't understand much of what he says.

[@structurefree]

the 5 kinematic equations in physics are typically derived for 1-D motion. projectile motion is a 2-d problem that usually reduces to 2 eqns and 2 unknowns...one equation in the x-direction, one eqn. in the y-direction.

[@LayChonkyHampters]

yo yo almost aced my dynamics quiz yesterday. sooo thanksss aloooottttt

[@ManuelSilva-lv6un]

This video is badass

[@cabqari1697]

Its amazing to be here after 9years😃Why y'll don't wait me?😄Hope Y'll are pro Enginers

[@Alen069]

8 years later...

[@structurefree]

Still ballin

[@Alen069]

@@structurefree that's what i call dedication! Thanks for the content😎😁

[@stevenknudsen7902]

looks like very mathematical introduction. Good, though, I have to say.

[@blackmoon3916]

Very helpful. Thanks alot.

[@rabbi_art]

You are boss

[@WHY70122]

I don't think it's easier than the 5 kinematics equations in PHYSICS, or chances that I just got into Dynamics and haven't found out how to attack a problem.

[@cmackatlanta]

So how would I calculate the angle of initial projectile and angle of impact on a parabolic trajectory? If I were given a ballistics chart with velocity and drop at certain distances? For example trajectory leaves at 290 feet height traveling a distance of 2000 feet hitting an object at 30 feet from the ground... What would be the angle it hits the target as well as the angle it was shot?

[@ahmadhelmy_]

I've a question, I don't understand how the acceleration in the x-direction is 0, I understand the ball is accelerating in the y direction, but I think of it a directly proportional relation; as in, as the ball accelerates in the y direction, it moves a distance in the x...I would only think of it as 0 in the x if the ball is literally going up and down in the y...Can anyone clarify this point for me?

[@wrenchesinthegears]

The velocity in the X direction is always constant, therefore acceleration (which is the time derivative of velocity) is zero. This is only if we analyse the projectile once it has already been launched(not as it is being launched). Once it is launched there are no external forces acting on the particle in the x direction ( ignoring air resistance). If the acceleration in the x direction was not zero, then the x component of velocity would change.

[@Alex_Interests]

If you were to draw the free body diagram of the object, then you would notice that the only force acting on it is gravity assuming there are no other external forces. Therefore, there are no forces in the horizontal direction which means the sum of forces in the horizontal direction is zero. When force sum is zero that implies F=ma=0. Or in other words, acceleration is equal to zero. And when acceleration is zero we can determine two things: velocity is zero or velocity is constant. Since the object had an initial velocity in the horizontal direction, then it must be constant. My tip is to just draw free body diagrams and use force analysis. This will solve most if not all problems.

[@eksp.1]

Very useful in this pandemic-era

[@Ubergeekpie]

Your voice sounds like FouseyTube

[@live-concept]

+Ken Burns haha it does!!

[@thenineminus1]

Could someone explain why is there no horizontal acceleration? Never understood why that is.

[@mindeater2]

+Christian Orozco There is no horizontal force on the cannon ball once it is in flight. there needs to be a constant force to produce acceleration. If we factored in wind resistance there would be a negative acceleration in the x direction.

[@thenineminus1]

Thank you mindeater2! It all makes sense

[@structurefree]

+mindeater2 balla!

[@WHY70122]

By the way, can somebody please explain me why I got the wrong answers when solving Dynamics problem using the 5 kinematics equations? struturefree, (sorry that i dont know your real name) can you make a video that explains steps to solve Dynamics projectile problem please?