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CK
Lv 4
CK asked in Science & MathematicsEngineering · 8 years ago

A projectile is fired with an initial speed of 250m/s, angle of 60deg, at height of 110m.?

Multivariable Calculus

a) Find the range of the projectile

b) Maximum height

c) Speed at impact

So I found the y component to be [250(m/s)*sin(60) + 110m]

and assuming gravity is y=[-9.8(m/s^2)]

I set them equal to each other and solved for s and got [33.317s]

I then got the x comp as [250cos(60)] and multiplied it by [33.317s] and got [4164m],

This is not right and am not sure where to start...

1 Answer

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  • 8 years ago
    Favorite Answer

    First, break its velocity vector down into position components, x and y, using a right triangle, calculus, and some common sense:

    dy/dt=250*sin(60deg) - 9.8*t

    integrate with respect to t to get equation for y, note that C=110 meters in this case

    dx/dt=250*cos(60deg)

    integrate with respect to t to get equation for x

    Now that you have your two position functions, everything else is a piece of cake:

    a) find t when y=0, pick the larger of the two solutions plug t-value into x equation to find range

    b) find when dy/dt = 0 to get maximum height

    c) plug t-value from part a into both velocity equations to get parameterized velocity at impact, then use pythagorean theorem to recombine them into vector form (dy/dt ^2 +dx/dt ^2 = dy/dx ^2 in this example)

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