A bullet initially moving with a velocity 20ms strikes a target and come to rest after penetrating a distance 10cm in target. Calculate the retardation caused by the target.
average speed in block= 10m/s
time to go .1 m n block= .1/10m/s=.01sec
force*time= changemomentum
and change in momentum is massbullet*20m/s
so you need mass bullet
See previous solution (under related questions):
http://www.jiskha.com/display.cgi?id=1337537113
In order to calculate the retardation caused by the target, we need to use the equations of motion.
The first equation of motion is:
v^2 = u^2 + 2as
Where:
v = final velocity (in this case, 0 m/s as the bullet comes to rest)
u = initial velocity (20 m/s)
a = retardation (what we are trying to find)
s = distance traveled (10 cm, which is equivalent to 0.1 m)
We can rearrange the equation to solve for a:
a = (v^2 - u^2) / (2s)
Substituting the given values:
a = (0^2 - 20^2) / (2 * 0.1)
a = -20^2 / 0.2
a = -400 / 0.2
a = -2000 m/s^2
Therefore, the retardation caused by the target is -2000 m/s^2. The negative sign indicates that the retardation is in the opposite direction of the initial velocity.