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A ball is launched from the ground at an angle of 45° with an initial velocity of 19.7 m/s. (a) What is its velocity at the top of the trajectory? (remember that it has both and x and y components when it leaves the ground) (b) What is its maximum height? (c) What is its range? (d) How long was it in the air?

Respuesta :

Explanation:

Given that,

Initial velocity = 19.7 m/s

Angle = 45°

(a). We need to calculate the velocity at the top of the trajectory

Using formula of velocity at the top of the trajectory

[tex]v_{y}=u\cos\theta[/tex]

Put the value into the formula

[tex]v_{y}=19.7\cos45[/tex]

[tex]v_{y}=13.93\ m/s[/tex]

The top of the trajectory is 13.93 m/s.

(b). We need to calculate the maximum height

Using formula of height

[tex]h=\dfrac{(u\sin\theta)^2}{2g}[/tex]

Put the value into the formula

[tex]h=\dfrac{(19.7\sin45)^2}{2\times9.8}[/tex]

[tex]h=9.90\ m[/tex]

The maximum height is 9.90 m.

(c). We need to calculate the range

Using formula of range

[tex]R=\dfrac{u^2\sin2\theta}{g}[/tex]

Put the value into the formula

[tex]R=\dfrac{19.7^2\times\sin2\times45}{9.8}[/tex]

[tex]R=39.6\ m[/tex]

The range is 39.6 m.

(d). We need to calculate the time

Using formula of time

[tex]t=\dfrac{2u\sin\theta}{g}[/tex]

Put the value in to the formula

[tex]t=\dfrac{2\times19.7\sin45}{9.8}[/tex]

[tex]t=2.84\ sec[/tex]

The time is 2.84 sec.

Hence, This is the required solution.