Answer:
(i) the resistive force exerted by the sand on the bullet is - 1 x 10āµ N
(ii) the time taken by the bullet to come to rest is 1 x 10ā»ā“ s
Explanation:
Given;
mass of bullet, m = 10 g = 0.01 kg
speed of the bullet, v = 10Ā³ m/s
distance traveled by the bullet, d = 5 cm = 0.05 m
(i) the resistive force exerted by the sand on the bullet
the acceleration of the bullet is given by;
vĀ² = uĀ² + 2as
0 = (10Ā³)Ā² + a(2 x 0.05)
-0.1a = (10ā¶)
-a = (10ā¶) / 0.1
a = -1 x 10ā· m/sĀ²
The resistive force is given by;
F = ma
F = (0.01)(-1 x 10ā·)
F = - 1 x 10āµ N
(ii) the time taken by the bullet to come to rest.
v = u + at
0 = 10Ā³ + (-1 x 10ā· t)
1 x 10ā· t = 10Ā³
t = 10Ā³ Ā / 10ā·
t = 1 x 10ā»ā“ s
