A bullet m9ving at a speed of 10m/s strikes a wooden plank . The bullet penetrates the plank 2cm deep and remains embedded in it . The acceleration of the bullet is?

d = .02 meters

average speed = 5 m/s

time = .02 meters/ 5 m/s = .004 seconds

a = change in speed / time
= -10/.004 = -2500 m/s^2

or
d = 10 t + (1/2) a t^2
.02 = .04 + (1/2)a 1.6 *10^-5
.02 = .04 + .8*10^-5 a
.8 * 10^-5 a = -.02
a = -2500 again

To find the acceleration of the bullet, we can use the equation of motion that relates the initial velocity (u), final velocity (v), acceleration (a), and distance traveled (s):

v^2 = u^2 + 2as

In this case, the initial velocity (u) of the bullet is 10 m/s (given). The final velocity (v) of the bullet is 0 m/s since it comes to rest after penetrating the wooden plank. The distance traveled (s) is the depth of penetration, which is 2 cm or 0.02 m (converted to meters).

Substituting the known values into the equation, we have:

0^2 = 10^2 + 2a(0.02)

Simplifying the equation, we get:

0 = 100 + 0.04a

Rearranging the equation, we find:

0.04a = -100

Dividing both sides of the equation by 0.04, we get:

a = -100 / 0.04

Calculating the value, we find:

a ≈ -2500 m/s^2

Therefore, the acceleration of the bullet is approximately -2500 m/s^2. The negative sign indicates that the acceleration is in the opposite direction of the initial velocity.