Can you work out a question on projectile motion if you are only given the total distance and the angle?

Question

For example 30 degrees and 40 meters (do you need another veriable)

Answer 1

No, those variables are sufficient. Since the simple mechanics equations for projectile motion only require distance, initial velocity and acceleration, and assuming air resistance is negligible, if the person has a basic knowledge of vector algebra, the question is fairly simple to answer.

Answer 2

Uh, well, assuming it is launched from the ground and wasn't moving to begin with... and 40 meters if your distance, you should be able to figure out how fast it is going and then how long it took.

There is your other variable. Just remember to break the angle into x and y components. You have your distance in y so then solve for v in y...

Write down all your givens just to make sure. Give me the newtonian motion equations and I can check but yea, you can do it yourself lol.

Answer 3

hi, Shrek is sweet, you do not ought to remedy for time. you'll get rid of the time through fixing simultaneous equations Time for ball to flow up and back down, utilising y-element t=2*v*sin45/g Horizontal distance traveled through the ball in that element X = v*cos45*t Now purely shove the first equation into the 2d X = v*cos45*t X = v*cos45*(2*v*sin45/g) sparkling it up a touch X = (2 * v^2 * sin45 * cos45)/g X = (2 * (6 m/s)^2 * sin45 * cos45)/9.80 one m/s^2 X = 3.sixty seven m so as you will locate, you could remedy for time is you want, yet you do not favor to remedy for time. continuously attempt to maintain your equations with all the variables, in case you could, till the very very last step. each in certain situations they could purely fall away, and also you've wasted "calculator time" for not something. i imagine that shrek advantages the great answer, I purely stole his equations and elaborated a touch. good success!

Answer 4

Well..... You **do** have to know the acceleration of gravity. But that's a constant and, on Earth, it's 9.8 m/s² so I'd say the answer is yes.

But that also neglects real-world stuff such as atmospheric 'drag' ☺


Doug

Answer 5

yes,it is sufficent.
the projectile motion on xy axis is governed my two equations,

y(displacement)=(usin(z))(t)-(.5)(g)(t^2)
x(displacement)=(ucos(z))(t)

there are 5 unknown variables,so we need atleast 3 informations
here in the question there are two explicit informations and one implicit information (i.e)y displacement is zero.
therfore we have the required information to find all other parameters.

Answer 6

Those two are enough.