Which one of the following statements is correct for an object released from rest?
Correct answer: A. The average velocity during the first second of time is 4.9 m/s
- A. The average velocity during the first second of time is 4.9 m/s
- B. During each second, the object falls 9.8 m
- C. The acceleration changes by 9.8 m/s² every second
- D. The object falls 9.8 m during the first second of time
Explanation
Since the object starts from rest and gains velocity due to gravity, its average velocity during the first second is 4.9 m/s.Given:The object is released from rest, so u=0 m/s Step 1: Motion under gravitySince the object is released from rest and falls freely, It is accelerating due to gravity, g=9.8 m/s^2 Step 2: Velocity after 1 secondUsing the equation of motion:v=u+(g)(t)v=0+9.8(1)=9.8 m/s The final velocity is 9.8 m/s downward.Step 3: Average velocityFor uniform acceleration, the average velocity is:v(avg)=(u+v)/2v(avg)=0+9.8/2 =4.9 m/s
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