Physics 3: Motion in 2-D Projectile Motion (12 of 21) Example 1: Plane Dropping Object
Vložit
- čas přidán 19. 08. 2013
- Visit ilectureonline.com for more math and science lectures!
In this video I will show you how to calculate the angle needed and distance traveled of an object dropped from an airplane.
You are an incredible teacher. I've watched this entire playlist before my physics exam, and I feel so much more confident than I did before. Thank you so much!
this man is a life saver
Gets to the point CLEARLY and SWIFTLY he really knows his stuff unlike some others who overcomplicate and extend an explanation
We appreciate the comment.
Best physics playlist on CZcams by far. Greetings from Italy
Another good video. You're such a good teacher sir. And I really needed this. Thank you!
Since the time taken for the package to cover parabolic distance is more than the time taken to cover vertical distance only
I found my physics teacher this semester :)
Very well explained Thanks
This is the most helpful video I have seen during this past term in my physics course. Thank you so so much for this massive help.
Glad it was helpful!
Thank u sir , it is very needed for me.
It would be interesting to use the quadratic equation coupled with the formula for arc length to see if that would be an acceptable method for determining the actual distance traveled.
Yes, but finding the length of the quadratic curve may be challenging.
thank you very much for this.. advance review :)
Thanks for this info! I wonder how this will be solved if the boy scout is moving at a certain velocity
We have similar examples where the target is moving.
great video
Excellent teaching
Thank you so much sir🙏🙏
very nice >>>but i am facing problem with such example that ,the target has some velocity .so we have two horizontal velocity for plane and target any one help me ????
How can you solve the problem by flight time for vertical distance .I dont understand
Any insight if you need to calculate speed and a plane is descending?
If the plane is traveling at an angle, the initial velocity will have a vertical component as well.
Thanks .l want your channel than anyone else.Sir please am confused about the formula and is 2y at opposite side.
Sorry, I don't see a "2y" anywhere.
I need help on a probem similar to this one: The height of a helicopter above the ground is given by h 5 3.00t3, where h is in meters and t is in seconds. At t 5 2.00 s, the helicopter releases a small mailbag. How long after its release does the mailbag reach the ground?... I start to solve the problem and get that the height of the helicopter is 24 m when it drops the package but then when calculating average velocity my professor gets vy=dm/dt=(d(3t^2))/dt=9t^2. I understand that the time is now to the second power but I don't get why he gets 9. Someone help pls. :)
The derivative of a t^b is: d/dt (a t^b) = axb t^(b-1) therfore d/dt (3t^3) = 3x3 t^(3-1)
Great Video
Taking PHY150 this term in college... you just helped me understand the concept better than the textbook did. And in a fraction of the time. Gotta be quick on one's toes for the calculations in this video, though. :D
Where are you taking physics 150? I taught physics 150 some years ago.
@@MichelvanBiezen Southern New Hampshire University.
Thank you verry much
thanks!!!!!! I learned so much from this video I owe you my first born child
You don't need to go that far. A simple thank you will suffice! 🙂
Thank u sire!
Why we can't take final velocity to be 0 and then use third equation of motion to find distance in x direction ??
cuz final velocity aint zero in any plane of motion
Thank you!!
great presentation... but... if a B-25 bomber is short on fuel, flying 350mi/hr, at 7km altitude, it weights 10 tons, if dropping off 100kg of weight -- for how many more miles (approximately) it will fly being 100kg lighter (9,900kg)??? THANK YOU
for this you would require the quantity of fuel and the rate of fuel consumption so without these values this question is unanswerable. Also you will need more values if the plane changes speed with it's loss of weight, though I guess you are implying the pilot keeps it the same.
Thank you
2:20 if you drop the package 1000 meters before the boy scout, wouldn't it land 10 meters ahead of the boy scout, since the package has to travel 1010 meters before it hits the ground?
Great playlist by the way.
Tq for giving more information
Sir, is the x in your given, the displacement of the object along the horizontal (x-axis)?
Thank you!!!
Yes it is the displacement along the x-axis.
saved my life!
How can you find the flight time by the equation s=it+1/2at^2
The flight time for the vertical distance MUST be the same as the flight time for the horizontal distance.
Dear Sir! thanking you very much, it is great. I have seen all of the lectures and persuading my son to watch all of these. I also tried to verify the value of angle found in the above example- that is 63 degree- by putting it into the general equation and I observed that the values verify with each other when the angle is 27 degree (90 Degree -63 Degree). If my understanding is correct or I am missing something?
The angle is part of the triangle with the opposite side = 2000 m and the adjacent side = 1010 m To find the angle we take the inverse tan of (2000/1010) = 63 degrees
Why do we calculate the angle by distance components and not by velocity components?
You need a strategy to solve the problem. Find out how long the projectile stays in the air (vertical component). Then realizing that the velocity in the x-direction remains constant: distance = Vx x time
Wouldn't the angle of theta alter the velocity in the y axis? So the initial speed wouldn't be zero would it.
Whenever you drop something from a stationary object or an object that is moving in a horizontal direction, the intial velocity in the vertical direction will be zero.
@@MichelvanBiezen Thank you for the reply!
So what role does the angle play in this scenario? Initial velocity being zero implies the object freefalls, so the angle wouldn't be needed
thanks u!
Have enjoyed the lecture
Glad to hear that 🙂
why is g negative (-9.8) in this case ? as the food is dropped and going down shouldn't g be positive?
When using the equations of kinematics down is negative and up is positive. Since the acceleration due to gravity acts in a downward direction, it is negative.
in this example, is the air resistance is being neglected? or do you consider it?
We ignore air resistance in these problems.
Michel van Biezen if your ignoring air resistance than please use another example. I doubt this aircraft is flying 50m/s in a vacuum chamber. If you wanted to use this example why not include the air resistance in the calculations. Otherwise this is math for a 12 year old.
why is it the initial velocity of y component is 0?
Since the object was dropped it will only have an initial velocity in the x-direction (the direction of the plane). Any object that is dropped will not have an initial velocity in the y-direction.
is there a way to answer a question like this if you are only given the velocity of the plane and nothing more?
+Orlando Castillo
So you are given the velocity of the plane (magnitude and direction), but no height? Then you cannot solve for how long it takes for a dropped object to reach the ground.
Sorry I meant to say I want to find the velocity of the package in both the x and y directions but with only the velocity of the plane given
+Orlando Castillo
Ahh, now I understand.
In the x-direction it is easy. It will be the same as the velocity of the plane (Ignoring wind resistance off course)
For the y-direction you'll need to find the time in the air. Then you use the equation: v = g * t
Professor I’m confused. When you say since there is no Vi away from the angle in either the X or Y direction we don’t have to find the components. Is the velocity the plane is traveling in the X direction constant which is why this can’t be considered as initial velocity?
Yes, the velocity of the plane is constant.
i agree, the angle theta should be zero on this case. otherwise, the time in the air should have been less than 20.2 sec((16,1622 sec) because of the initial Viy velocity. @-63degrees, the range would be 366.88
Can we increase the distance traveled by the object by increasing the speed of the plane, allowing it to be dropped beyond 1000 meters to reach its target?
That is indeed correct.
(or drop it from a greater height)
How do I know if the y is final or initial ?
Yo is the initial y is the final
How did you calculate the arctan? Thanks!
Some calculators have a button for that. He did the division inside the arctan and then pressed arctan.
if you please i wanna ask a question, the angle theta which's below the horizon must be 360 - 62?
In mathematics, we use the concept of angles that are not necessarily related to the real world. Therefore in mathematics we say that an angle of 60 degrees is equal to an angle of 420 degrees. But in the real world everyone know that cannot be true. Just like in a triangle there is no such thing as an angle which is greater than 180 degrees. So in the diagram the angle referenced is an angle of 62 degrees.
@@MichelvanBiezen thanks for replying dr❤️💐
Cool practical example! 😅
Thanks! 😊
When is y initial 2000 and when is y final 2000 and when are they negative kind Sir?
It depends on your reference point. Typically we let the ground equal zero height and thus the starting height is positive. You could let the starting point be zero height and then the final height will be negative. You can solve the problem either way.
How’d you get 4.9t^2? For acceleration aka the *g* variable
Never mind I got it
Can you tell me how did he get that sir?
@@bitrixgaming5059 He divided gravity (9.81m/s^2) by the 1/2
@@davidvazquez4322 how did he get the gravity?
Thank you!
You're welcome 😊!
,does the dist 'x' refer to only the dist between bomb n the man?.....I got a bit confused by the labelling of 'x' in the diagram u have drawn
x is the horizontal distance from where the package is dropped to the hiker.
Okay thnq
why you dont need to find the component of that ball?
Riqy Rizqyandra
The time in the air only depends on the y-component (free fall)
What if you don’t have the height though?
Then you cannot solve the problem
Where did the 4.9 came from?
4.9 = (1/2) g = (1/2) 9.8
I don't understand where the 4.9 was obtained.
4.9 = (1/2) 9.8 The equation for time in the air is: y = (1/2) g t^2 where y is the starting height
If you could respond how did you get 4.9?
4.9 = (1/2) g
This was awesome!
Glad you think so. Thank you.
Predator Drone has entered the chat
sir why the y is equal to zero even it cover h distance in vertical direction
It is typical to call y = 0 at the ground level. (We could call the height of the plane as y= 0 and then the ground would be y= -h
Please tell me
Very helpful
Glad you think so! 🙂
if it lands behing him, he won't notice, so it wont do him any good
thank you bro
You're welcome!
Half g = 4.9 but how did you get that minus?
When using the equations of kinematics, direction is important. Since the acceleration of gravity acts downward, we need that negative sign.
@@MichelvanBiezen gotcha. Should have mentioned that
an airplane is flying with a velocity of 90 metre per second at an angle of 23 degree with the horizontal when the plane is 114 m directly above a dog that is standing on level ground a suitcase drops out of luggage compartment how far from the dog will suitcase land
The problem is solved as if there is no plane. On object with an initial velocity of 90 m/sec is thrown from a height of 114 m above the ground at an angle of 23 degrees above the horizontal. How far away with the projectile land? There are examples exactly like that in this playlist.
ans: Range is 795.33 meters(from the dog's location at the time of drop), flight time is 9.6001 sec
Since the plane is falling down the height should be -2000m isn't
The plane is maintaining the same height.
Michel van Biezen I got it thank you so much
where did u get 1010???
pls reply asaP
50 X 20.2 = 1010
Why is he subtracting 4.9t^2. The formula clearly says +1/2gt^2
When using the equations of kinematics, we need to take into account the directions. Since g acts downward (this is a negative direction), we must place a "-" sign in front of it.
@@MichelvanBiezen thank you that makes sense
omg you are an angel i love you i can see your wings its a rounded shaped wings
No, no, just a simple man trying to do his small part in the world.
Where did he get the 4.9??
+Sofia Murillo
g = - 9.8 m/sec^2
(1/2) g = - 4.8 m/sec^2
+Sofia Murillo Maybe you should realise that the acceleration due to the force of gravity is equal to -4.9 m/s^2.
+Brent P 1/2(g)(t)^2 the acceleration due to gravity is 9.80665m/s^2 not 4.9. Just saying. :P
+Sofia Murillo half of 9.8?
I LOVE YOU
thank you. Glad you like our videos.
If it is 20.2 sec
Then final should be 1006 meters.
50*20 +0.2*60*50/100
Are you referring to: 50 m/sec x 20.2 sec = 1010 m ?
You just found the flight time for vertical distance
Where tf did the 4.9tsquared came from
(1/2) g = (1/2) (9.8 m/sec^2) = 4.9 m/sec^2 g = the acceleration due to gravity
@@MichelvanBiezen I actually understand it when looking at it but thanks anyways
so if i throw a paper airplane inside of an airplane the opposite direction of the travel of the plane will that plane hit someone at a massive amount of speed and kill them? why aren't we warning people eat airports to NEVER throw anything in the airplane the opposite direction of flight. you can always throw up to the cockpit.
+Bo Huggabee No, that is not the case.
+Bo Huggabee How on Earth would you come to that conclusion from this video? Relative velocities would entail that throwing something in a plane, that has zero turbulence, would be no different for the people in the plane than if it was thrown from the ground. Actually, Earth itself is moving way faster relative to the galaxy than a plane does, but that doesn't effect us because so are we. Relative velocities. Think about it.
***** its atmospheric pressures. lol
Atmospheric pressure differences do affect stuff, but don't matter in this case. If you're on a plane, your relative velocity with respect to the plane is 0 m/s, NOT the speed of the plane. So from your reference frame the projectile is moving at the speed that you threw it. You don't add the speed of the plane. You only add the speed of the plane if your reference frame is the Earth. From the passenger's reference frame, the plane is still since it's moving at the same velocity as the passengers. You can play ping pong on cruise ships. Uniform motion is not a problem, only acceleration.
***** do you read the things you say?
why didnt you give the guy a turban?
Great video as always!! But why is acceleration due to gravity negative if the object is falling downwards. doesn't g become positive if an object is falling downwards. please help🥲
When you use the equations of kinematics, it is fundamental that you use a -9.8 because the acceleration due to gravity is directed downward.
tha man
Approximately 10.10 seconds
he made first equation more comlicated
time in the air?? seriously?
Why not?
@@MichelvanBiezen I spent a lot of mental energy to figure out what it meant, maybe calling it "projectile's duration in the air" instead would have been more explanatory
Subtle gru
Vi
Vf
d
a
t
🤮