Final answer:
The time it takes for a bullet fired upwards at a speed of 350 m/s to come to rest before falling back down is approximately 35.7 seconds, calculated by using the acceleration due to gravity.
Step-by-step explanation:
The question is asking for the time it takes for a bullet fired straight up at a speed of 350 m/s to come to rest before it starts falling back to the ground. The calculation involves using the concept of acceleration due to gravity, which is approximately 9.81 m/s2 downward. Since the bullet is moving upward against gravity, it will decelerate at this rate until its velocity becomes zero at the peak of its trajectory.
To find the time taken to reach this point, we use the equation final velocity = initial velocity + (acceleration × time). Setting the final velocity to zero (since the bullet comes to rest) and rearranging the equation to solve for time (t), we have: t = - (initial velocity) / (acceleration due to gravity). Substituting the given values, we get: t = - (350 m/s) / (-9.81 m/s2) = approximately 35.7 seconds.