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kogti [31]
3 years ago
9

A ball is launched at an angle of 10 degrees from a 20 meter tall building with a speed of 4 m/s. How long is the ball in the ai

r, how far from the launch point does it land, and what is the maximum height the ball reaches with respect to its starting height? a) -1.85 s,8.71 m, 1.54m b) 2.21 s, 8.71 m, 1.54m c) 6.44 s, 4.23 m, 0.02 m d) None of the above
Physics
1 answer:
shutvik [7]3 years ago
7 0

Answer:

d) None of the above

Explanation:

v_{o} = inituial velocity of launch = 4 m/s

θ = angle of launch = 10 deg

Consider the motion along the vertical direction

v_{oy} = initial velocity along vertical direction = 4 Sin10 = 0.695

m/s

a_{y} = acceleration along the vertical direction = - 9.8 m/s²

y = vertical displacement = - 20 m  

t = time of travel

using the equation

y=v_{oy} t+(0.5)a_{y} t^{2}

- 20 = (0.695) t + (0.5) (- 9.8) t²

t = 2.1 sec

consider the motion along the horizontal direction

x = horizontal displacement

v_{ox} = initial velocity along horizontal direction = 4 Cos10 = 3.94 m/s

a_{x} = acceleration along the horizontal direction = 0 m/s²

t = time of travel =  2.1 s

Using the kinematics equation

x =v_{ox} t+(0.5)a_{x} t^{2}

x = (3.94) (2.1) + (0.5) (0) (2.1)²

x = 8.3 m

Consider the motion along the vertical direction

v_{oy} = initial velocity along vertical direction = 4 Sin10 = 0.695

m/s

a_{y} = acceleration along the vertical direction = - 9.8 m/s²

y_{o} =initial vertical position at the time of launch = 20 m  

y = vertical position at the maximum height = 20 m

v_{fy} = final velocity along vertical direction at highest point = 0 m/s

using the equation

{v_{fy}}^{2}= {v_{oy}}^{2} + 2 a_{y}(y - y_{o})

0^{2}= 0.695^{2} + 2 (- 9.8)(y - 20)

y = 20.02 m

h = height above the starting height

h = y - y_{o}

h = 20.02 - 20

h = 0.02 m

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The answer is to this question is B
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A rocket is launched from the surface of Earth with a speed v0 that will allow the rocket to escape the gravitational field of E
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Answer:

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