A bullet traveiling horizontally at aspeed of 350 m/s hits a board perpendicular to the surface, passes through it, and emerges on the side at a speed of 210m/s. if the board is 4.oo cm thick, how long does the bullet take to pass through it?
The average speed of the bullet passing through is (1/2)(350 + 210) = 280 m/s. Divide the thickness (4*10^-2 m) by that speed to get the travel time.
.004/280=1/70
To find the time it takes for the bullet to pass through the board, we can use the equation:
time = distance / speed
First, we need to determine the distance the bullet travels through the board. Since the bullet is traveling horizontally and perpendicularly to the board, the distance it travels through the board is equal to the thickness of the board.
Given:
Speed of the bullet before hitting the board (v1) = 350 m/s
Speed of the bullet after passing through the board (v2) = 210 m/s
Thickness of the board (d) = 4.00 cm = 0.04 m
Distance = Thickness of the board = d = 0.04 m
Now, we can calculate the time it takes for the bullet to pass through the board:
time = distance / speed
time = d / (v2 - v1)
Substituting the known values:
time = 0.04 m / (210 m/s - 350 m/s)
time = -0.04 m / (-140 m/s)
time = 0.04 m / 140 m/s
time ≈ 0.00029 seconds
Therefore, the bullet takes approximately 0.00029 seconds (or 2.9 x 10^-4 seconds) to pass through the board.