Final answer:
To find the height (h) from which the bullet is fired, we can use the equations of motion for projectile motion. Using the given information, we can calculate that the bullet was fired from a height of 90 meters above the ground.
Step-by-step explanation:
To find the height (h) from which the bullet is fired, we can use the equations of motion for projectile motion. Since the bullet is fired straight upward, the time it takes to reach the ground is equal to the time it takes to go up and come back down. So, the total time of flight is 10 seconds.
We can use the equation h = vit - 0.5gt2, where h is the height, vi is the initial velocity, t is the time of flight, and g is the acceleration due to gravity. Plugging in the values, we have h = 40*10 - 0.5*9.8*10*10 = 400 - 490 = -90m.
Since the height cannot be negative, the bullet must have been fired from a height of 90 meters above the ground.