Hello
The bullet is moving by uniformly accelerated motion.
The initial velocity is

, the final velocity is

, and the total time of the motion is

, so the acceleration is given by
where the negative sign means that is a deceleration.
Therefore we can calculate the total distance covered by the bullet in its motion using

So, the bullet penetrates the sandbag 1.8 meters.
Answer:
(A)
Explanation:
We know , electric potential energy between two charge particles of charges "q" and "Q" respectively is given by kqQ/r where r is the distance between them.
Since the two charged particles are moving apart, the distance between them (r) increases and thus electrical potential energy decreases.
Give u = start velocity
v = end velocity
v = u + at
50 = 400 + a*30
30a = -350
a = -116.67 m/
**Why the accecleration is negative number**
Because displacement, velocity, and acceleration are VECTOR QUANTITIES.
Vector Quantity must have direction.
V = f(wavelength)
22.0 = 0.0680 (wavelength)
wavelength = 323.52 m