A ball is thrown vertically up into the air from a window ledge 30 meters above the ground with an initial velocity of 10m/s. Find velocity of ball after 2 seconds.
Correct answer: A. 9.6 m/s
- A. 9.6 m/s
- B. 29.6 m/s
- C. 19.8 m/s
- D. 2 m/s
Explanation
To find the velocity of the ball after 2 seconds, use the equation of motion v = u + at, where 'u' is the initial velocity, 'a' is the acceleration (gravity, which is -9.8 m/s² when considering upward motion), and 't' is the time. Here, u = 10 m/s, a = -9.8 m/s², and t = 2 seconds. Substituting these values, v = 10 + (-9.8) * 2 = 9.6 m/s. Option A is correct because it matches this calculation. Option B is incorrect as it suggests a significant increase in velocity, which is unrealistic given the deceleration due to gravity. Option C is incorrect due to a likely misapplication of the formula. Option D is incorrect as it underestimates the velocity significantly.
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