A bullet fired vertically upward from a gun held 2.0 m above the ground reaches its maximum height in 4.0s. calculate its initial velocity.
[g = 10ms\(^-2\)]
10 ms-1
8 ms-1
40 ms-1
20 ms-1
Explanation
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Discussions (9)
At the highest point, the velocity becomes zero.
We use the equation of motion: v = u − gt
At maximum height: v = 0
t = 4.0 s
g = 10 m/s²
So:
0 = u − (10 × 4)
0 = u − 40
u = 40 m/s
Final answer:
Initial velocity = 40 m/s
The “2.0 m above the ground” is just extra information here. It doesn’t affect the time to reach maximum height, so it doesn’t change the initial velocity.
You can also solve it using the projectile formula. The 2.0m parameter given is just for confusion🤌
I'd love to see how we can further solve for maximum height from here, because the angle is not provided.
