Question

A bullet traveling at a speed of 100ms⁻¹ strikes a wall and penetrates 2cm. How long does the bullet take to stop after striking the wall?

Answer 1

V² =u² +2as
O² =(100 × 100) +2 × 9 × 0.02m
a= −10000 =−2.5 × 10⁵m/s 
     2 × 0.02
v= u + at 
O = 100 + − 2.5 × 10⁵ × t
 t =    100       = 4 × 10⁻⁴s 
      2.5 × 10⁵