What is Projectile: Definition and 1000 Discussions
A projectile is any object thrown by the exertion of a force. It can also be defined as an object launched into the space and allowed to move free under the influence of gravity and air resistance. Although any object in motion through space (for example a thrown baseball, kicked football, fired bullet, thrown arrow, stone released from catapult) may be called projectiles, they are commonly found in warfare and sports. Mathematical equations of motion are used to analyze projectile trajectories.
I figured this would be a problem in some classical mechanics book but so far I can't find an answer anywhere. Assume there is no drag or lift, and since the planet is not rotating we don't have to worry about Coriolis effects. I'm working on a solution but I want to see if my work is correct...
my answer was D, which is correct considering the motion downwards eg, object thrown from a cliff
but what if an object is moving up?like a football being kicked?
i cant understand how this graph applies to that...
i solved it like this...
s = ut + 1/2 at^2
t= 1.08 (from part a)
u= 65 sin4.30
a= 9.81? or -9.81
the answer said -9.81
why? wouldn't acceleration change from -9.81 to +9.81 because it moves up then down???
its soo confusing...
Since the ball will follow a parabolic trajectory , i threw it into the coordinate plane with particle starting from the origin .
$$y= kx^2$$ Differentiating wrt ##t## : $$ gt=2ku^2 t\implies u=\sqrt{\frac{g}{2k}}$$ where $$k=\frac{\sin\theta}{R\cos^2\theta}$$ Now , final speed when it reached...
Hi - I built an air cannon to launch a fishing lure for my science fair project. The air cannon launched a 1/4 oz lure 31.4 meters. Based on this, I calculated the initial velocity to be 17.54 m/s using the formula for range of a projectile. I want to be able to launch the lure 38.5 meters. I am...
A ball is thrown with an initial speed vi at an angle 𝜃i with the horizontal. The horizontal range of the ball is R, and the ball reaches a maximum height R/8. In terms of R and g, find the following.
(a) the time interval during which the ball is in motion: Sroot(R/g) Correct
(b) the ball's...
1) Bullet spin causes a bullet to become a gyroscope. Specifically, bullets have their center of pressure in front of their center of mass. Therefore, when pressed, gyroscopic forces cause a bullet to spin 90 degrees instead of tumble. See this diagram:
2)The precession does not cause the...
TL;DR Summary: Hi, I am a high schooler competing in a science competition building a trajectory to shoot the projectile similar to the one in the thread below.
https://www.physicsforums.com/threads/aarons-gravitational-potential-energy-to-launch-projectile-science-competition.773745/
The 4...
Hi.
Very simplified schematics of railguns all look like this:
I have trouble properly understanding this. So apparently there is still a significant magnetic field where the projectile is, even though that's where the current stops flowing through the rails? Of course the magnetic field...
TL;DR Summary: Find initial vertically upward speed of the ball
Find horizontal speed of the speed
Find angle
How to:
Find initial vertically upward speed of the ball
Find horizontal speed of the speed
Find anglei try to solve it but it didn't work
TL;DR Summary: Find horizontal velocity?
I have no idea how to solve the problem, the question only provide distance 16cm(h),3.6cm(v) and acceleration = 0
(a) Find the initial speed.
Solution
The relevant equations are (4) and (5) derived here and reproduced below as (1) and (2) respectively:
$$\begin{align}
& \frac{\Delta x}{\tan\!\theta-\tan\!\varphi}=\frac{2v_{0x}^2}{g} \\
& \tan\!\varphi=\frac{1}{2}(\tan\!\theta+\tan\!\omega)...
For this problem,
The solution is,
I don't understand how they got from ##\frac {sin^2\theta_i}{sin2\theta} ## to ##\frac{tan\theta_i}{2}##. Would somebody please show me the immediate steps?
I also don't understand is why they say the ignore the trivial case where ##\theta_i = 0~rad##...
TL;DR Summary: Using vector functions how can I find the minimum average velocity (something greater than 11.86m/s) of a ball if the launch angle is unknown and if I have a point that the object must travel through (11.86, 3.47)?
In my assignment, I developed a function for a lob shot...
TL;DR Summary: I want to mainly figure out where in the problem solving I went wrong. I understand the correct answer (since I looked it up), but to me, it does not make any sense.
I am honestly stumped at this point. Online solutions say that my equation y = 0.5774x-0.003354x^2 should...
i used t=d/v for the x direction using the formula t=250/vcos55
and subbed that into the formula for the y direction
d = (v) (t) + (0.5) (a) (t)^2
35 = (vsin55) (250/vcos55) - (4.9) (250/vcos55)^2
canceled out the first two v
35 = sin55 (250/cos55) - (306250/v^2cos3025)
35 = 357 -...
My reasoning was to use this kinematic equation to first get time of flight of the baseball using horizontal components, and then use this same equation again to find initial velocity.
I worked myself into a trigonometry rut. I've tried two approaches, first by not changing the frame of reference, and second by taking the incline as the horizontal x axis. Here is my second attempt:
Take the incline as the horizontal. Then the coordinates of target T are:
$$
\begin{align}
x_T...
if the target is lower than me, the formula is below, but if it's higher as in the task, a whole different formula is required I think.
a = 9.8 * distance^2 / velocity^2
phi = Arctan(distance / height_diff)
angle_if_elevation = ( Arccos((a - height_diff) / Sqroot(height_diff^2) + distance^2)) +...
I have attempted the problem a few times, and have posted my work below. I thought to check my work using
## v_x t = v_1 \times \cos\theta \times t = \Delta x##
to see if I get back expected results, and I did for the horizontal motion (the substitutions are from the numbered steps below):
##...
We know x = R =max range (28m) on level ground. Need to find v()^2. Subbing y=0 into (1) above, get v(0)^2 = (gR^2/)/(2*cos (theta)^2 * tan (theta). ... (2)
This didn't seem right, since this means v(0)^2 is a negative number ... maybe my orientation or algebra wrong?
Anyway, didn't see...
I've been trying some online projectile problems. Specifically, I was using this one on master difficulty, looking at row e. It uses a random number generator; I shared the data I received in the Homework Statement above.
According to the help section, you can solve this with the formula...
26.6m/s = v0
36.5º = θ
g = 9.81m/s^2
A) Find Range:
(v0^2)/g *sin2θ = (26.6^2)/9.81 * sin2(36.5)
= 89.99
I double-checked with the other Range equation (2v0*cosθ * (v0sinθ)/g) so I know I'm doing something wrong. Please help! Thank you
edit: A) Correct answer is 69.0
I assumed the cyclist was going 60-kph. Then worked backwards as shown above to calculate the deceleration in the x direction and then the time to decelerate to a stop at 39 m. Then used this time to calculate the initial speed if cyclist thrown 39 m, which was 8.4 m/s. But if he was going...
I have a question about the Coriolis acceleration experienced by a projectile launched from the surface of a rotating body.
Say a ball is launched at 45 degree angle relative to the surface at some initial velocity v0. Let's further specify that the ball is launched due north from the equator...
Mentor note: Moved from a technical forum section, so Homework Template is not present.
Hello Physics Forums members,
I am a student in AP Physics C and I was just working out the range of a projectile when air resistance is non-negligible. As of right now I'm going to use the linear model of...
At first, I want to use conservation of momentum when the object explodes at the highest position but I think the projectile is not a closed system (there is weight acting on it). Tried conservation of energy but not enough information provided.
What approach should I take for this question...
Hi, so I solved this using energy. I also tried solving this using kinematic equations. The issue I am running into s for calculating the Vy of the problem. I am able to find the time it takes the rock to fall using d=(1/2)gt^2. Then, I considered two different ways of going about finding the...
So first I found the velocity of the ball at the bottom of the swing from the force equations, which I got to be 4.9 m/s and this is only in the x-direction. Then using the projectile motion for delta y I found time, which is 0.2s. Then using that time I found the delta x to be 0.98m.
I just...
Hi, I am a game developer and recently found myself in a situation where I wanted to create an enemy that shoots at you given a set of variables. The game takes place in a top down view so there is no need for gravity acceleration, just 2d linear constant movement.
The question to answer is...
So using the projectile equation I got ##a\sin (\alpha + \beta) = v\sin (\alpha + \beta)t + \frac{g\sin \beta t^2}{2}##
To find t we use the other projectile equation:
Since the horizontal velocity must be 0 for it to hit the ground perpendicularly we set the equation to be:
##0 = v\sin (\alpha...
Calculated maximum range of arrow at 45 degrees with initial velocity measured horizontally is of course reduced by air resistance. BUT initial velocity at 45 is reduced because propulsive force is constant and gravity reduces velocity by about 3m/sec. So not all distance loss is drag. Authors...
Assuming it’s one body whose initial speed is u. First it attains height h then H. t1 and t2 are two times at which they attain h and H.
##h=ut1-\frac12gt1^2##
##H=ut2-\frac12gt2^2##
##\frac {t1}{t2}=1/3## Replacing t2 with 3t1, I am stuck.
I found the function of the range of the projectile launched from a cliff.
R = vcos(x)((vsin(x))+sqrt(v^2sin^2(x)+2gh))/g
I stopped here because I feel like taking the derivative and optimizing for maximum would spiral out of control.
Is there another approach to this problem?
Givens:
Vyi=12.5 m/s
Vyf=-12.5 m/s (at the same horizontal level)
ay=-9.81 m/s^2
Δy= zero m (as the displacement on the y-axis, when the projectile reaches the same horizontal level, is zero m)
Δt=?
When I use
Δy=[(vyi+vyf)/2]*Δt
I get the time as undefined.
Δt= 2Δy/(vyi+vyf)
= 2*0 m/(12.5...
Hello everyone,
I have a homework about projectile motion experiment and I threw small ball over the table and ball did projectile motion at the end of the table and ı recording this motion on motion tracker and motion tracker gave me acceleration of y component of ball as 14.02 m/s^2. But it...
The first part is simple. ##10 secs = 0.0027 hrs##. $$0.7=290\cos30t$$
For the second part $$s=-290\sin30t-\frac129.8(0.0027)^2$$
But I am getting wrong result.
I know how it’s done. So let’s jump on the question. The displacement that came was negative 6 cm. I want to know how this formula describes perfectly negative displacements.
I don’t understand the mechanism. If I assume ##ut## to be distance traveled in absence of g then what is ##-1/2gt^2##...
I am trying to find the launch angle ##\theta## using the relationship:
##\theta=\arctan(\frac{v_{y}}{v_{x}})##
So, ignoring attenuation due to air resistance, we have a constant horizontal velocity:
##v_x = d_x/t = 95m/4.5s \approx 21 m/s##
But what value do we use for ##v_y## which is not...
Summary:: What propelling mechanism can get me most consistent shots?
Compressed air, spring powered, rubber band powered or any other
Hello, I am a high school student participating in a local competition where I have to make a turret.
Here are the rules:
1) The projectile has to fall in a...
When a ball is thrown such that it moves in a curved trajectory in the horizontal plane, it amuses me to think of its dynamics.
In motion of a ball thrown upwards the force of gravity gives it a parabolic trajectory
However when the ball is thrown to curve and hit a target, (in the horizontal...
So far all I have determined is the equations of motion for the two and that is as follows. It is trivial that y(t)=v1sin(Q)t -gt^2/2 and that x(t)=v2cos(Q)t. Now the angle that is anticlockwise from the negative horizontal of the robber is 90 - Q using basic trigonometry, using this we can...