A boy kicks a football with an initial velocity of 20 m/s at an angle of 25° above the horizontal.If we neglect air,the magnitude of the acceleration of the ball while it is in flight is A)25 m/s². B)18 m/s². C)9.8 m/s². D)8.5 m/s². E)0 m/s².

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Quizplus · Accepted Answer

Since air resistance is neglected, the only acceleration acting on the ball is the acceleration due to gravity, which is 9.8 m/s$^2$ downward. The initial velocity of the ball has a horizontal component of 20cos(25°) m/s and a vertical component of 20sin(25°) m/s. The horizontal component of the velocity remains constant during the flight, and the vertical component is affected only by gravity. Therefore, the magnitude of the acceleration of the ball while it is in flight is equal to the magnitude of the acceleration due to gravity, which is 9.8 m/s$^2$.

A Boy Kicks a Football with an Initial Velocity of 20