Physics Lesson: Projectile Motion Part 2 for High School

[tiggs1792]

im in college physics and you explained the material better than my professor with a phd. thank you very much

[luikahei1]

thx 

[Devantium]

Y u no do the V2v??? i never know what it is

[mrtsunny]

ive been having trouble with projectiles at an angle. thanks for clearing this up!

[IaMtheChiTownCp3]

Thanks my physics doesn't explain like you

[Arie5009]

thanks

[saxthekid19]

PhysicsEH - letting students pass physics since feb 12th 2010!

[HKGYoshiokaYui]

you really save my life.

[cool12threeman]

Thank you so very much for these lessons they are extremely clear and easy to understand. God will most certainly reward you in this life and in the hereafter...

[potionsmistressful]

the quadratic forumla... x equals negative b, plus or minus squareroot (of) b squared minus four a*c all over 2(a)

[NewYork026]

You are awesome. simple.

[jensons88]

good explanation. for those who are watching this video, you can also visit my channel. it features videos about a projectile motion program that automatically calculates the path towards another object. it uses physics equations to make it work. if you want to know more about how the program works, you can visit the web site that's on my channel

[jhoncena9111]

An arrow is shot at a 30(deg) angle above horizontal. It has a velocity of 49m/s. What is dh? 0m?

[hifatpeople]

this is 12th grade stuff? Well that explains why everyone in my class is a senior.

[Ranmitita]

THANKS A LOT!!!! Everything is so clear now...

[theuayub]

the most productive thing ever subscribed to!!!!!!

[PhysicsEH]

@Dinopikachu If you have the intital x and y components for the velocity you need to put them together to find the original velocity. Make a triangle out of the x and y components and use Pythagorus theorm to find the magnitude and then use inverse tan to find the angle. Check out our video titled "Physics Lesson: Vector components part 3" which shows you how to do this.

[iHateMyLifeGr]

Great lesson, helped me understand it more, thanks.

But I got a question, my problem is always about choosing the right equation because there are too many, but @ 3:14 in this video you said: "I can use my big five equations".

Can you mention these 5 equations please? I'll be grateful, thanks a lot!

[PhysicsEH]

@iHateMyLifeGr We have a video on our website. Youtube will not let me put the link here so go to the website listed in the description and look for Physics Lesson: Acceleration Equations Part1. I think it will help.

[iHateMyLifeGr]

@PhysicsEH It was very helpful, thanks a lot PhysicsEH you helped me understand physics better, now I know how to use the 5 equations :D

I wish you could come teach at my school xD

[commando1888]

how do you use the quadratic formula???which one is a or b or c???

[PhysicsEH]

@commando1888 d = V1t + 1/2 at^2 so for this one -40 = 100t - 4.9t2. You must rearrange it to be -4.9t^2 + 100t + 40 = 0 Which is like the form of the quadratic which is ax^2 + bx + c = 0 so a = -4.9, b = 100 and c=40. You need to look up the quadratic formula which will show you where to put a, b and c to calculate x (or t in this case). I can't write it here. I hope this helps.

[commando1888]

@PhysicsEH dude u r the best thanks a lot!!!

[Chatterjeepal]

you are my savior!

[PhysicsEH]

@Chatterjeepal Thanks for the comment, Glad to help.

[Jaclyn11495]

Thank you so much

[PhysicsEH]

@Jaclyn11495 Glad to help.

[l3aIIin23]

thanks SO MUCH

[PhysicsEH]

@l3aIIin23 Thanks for letting us know they helped. You're welcome.

[aZnExQuiZiTkiNG]

this is the best physics teacher ever. i understoood the whole chapter in less than 10 minutes while it took my teacher weeks.

[PhysicsEH]

@aZnExQuiZiTkiNG Thanks for letting us know they helped.

[AVerbene]

thank you so much

[PhysicsEH]

@AVerbene Glad we could help

[zombie09ful]

i have a question, arent we supposed ti multiply the 20 seconds by 2? like thats what i was told by my physics teacher, it went up then came down so thats why we have to multiply by 2

[PhysicsEH]

@zombie09ful Hi. Because I put in the initial velocity as (+) and the acceleration as (-9.8) the equation takes into account that the object gtoes up and then stops and then goes back down. You don't have to split the calulation up or multiply the time by 2. The time I caculated is the time to go up and back down to the height indicated. I hope this helps.

[zombie09ful]

omg u are a life saver, i am now understanding stuff coz before i wasnt able to!! please keep posting more please and thank you!!!!

[PhysicsEH]

@zombie09ful Thanks for the great comment. Glad to help.

[9418791850]

reallly niicee

worth concept clearing

[liamsbeterthancharli]

this is very good for me as i am in year eight and i am not aloud to do physics so i am really enjoying these video's

[PhysicsEH]

@liamsbeterthancharli We are glad you like them. Thanks for letting us know.

[MaQWan93machanG]

thanks alot.. really helpful

[PhysicsEH]

@MaQWan93machanG Glad we could help.

[CocodriloNYC]

Good stuff, thank you, please post more

[PhysicsEH]

@CocodriloNYC Thanks for letting us know you liked our videos. We plan on making more this year.

[Po2cupine]

can I change from using quadratic equation to find V(2v) and use the formula V(2v)=V(1v)+at ?  (I'm not good at quadratic equation)

[PhysicsEH]

@Po2cupine Yes, you can use that formula and then use another of the "big Five" acceleration formulas to find "t". Just make sure you use only the vertical information and be careful to put the correct sing (positive or negative) to each number. Sorry to take so long to reply, I was on vacation.

[jasonfok]

I want to ask

why the vertical distance is -40?

THat ball is projected upward

why it is not more than 40?

[PhysicsEH]

@jasonfok Hi. The distance really displacement. This is measured from start to finish. Since the ball started at the top and ended up at the bottom then the displacement from start to finish was from the top to 40m below where it started. Since up is positive then the 40m is negative. It does not matter that the ball went up at the start. All that matters is that the ball ended 40m below the start. I hope this helps.

[jasonfok]

@PhysicsEH I understand now! Thank You.

[jasonfok]

@PhysicsEH oh...thank you!

[jasonfok]

@PhysicsEH oh...thank you!

[vb4des]

I start love you :)

[PhysicsEH]

@vb4des Thanks. We love to hear that.

[AinahMAx]

you are LEGENDARY!

[PhysicsEH]

@AinahMAx Thanks for that enthusiastic comment. Glad to help.

[hersheybar11]

Please quit your job and come to my school!!!

[PhysicsEH]

@hersheybar11 Thanks for the compliment!

[Arphyn]

shit, better than my teacher! thanks a lot

[PhysicsEH]

@Arphyn Thanks, glad to help. Tell your friends about us.

[makio4991]

helped me a lot!! thanx