Question

plz answer it correctly plz​

Answer 1

Answer:

mass of bullet should be =10gm=0.01kg

initial velocity (U)of bullet=1000m/s

final velocity (V)=0m/s(because it has stopped after striking sand)

displacement of bullet=5cm=0.05m

a)using 2as=V ²-U²

2(a)(0.05)=0²-1000²

2a(5/100)=-1000000

2a(1/20)=-1000000

a(1/10)=-1000000

a=-10000000=-10power7

acceleration of bullet is -10power7or -10000000

by using F=ma

F=0.01(10000000)

F=1/100(10000000)

F=-100000N

there fore resistive force of bullet =-100000N

b)by using a=v-u/t

-10000000=0-1000/t

-10000000=-1000/t

-10000=t

or

t=-10⁴seconds

Explanation:

Answer 2

Answer:

Explanation:

initial velocity[u] = 1000 m/ sec

final velocity [v]  = 0 m/sec   [ bullet came to rest]

mass of bullet [m] = 10 g = 10/1000 kg

displacement = 5cm = 5/100 m

by third equation of motion

2as = v²-u²

2a ×5/100 = 0² - 1000²

2a ×5/100 = -1000000

  2a          = -1000000×100/5 = 100000000/5 = -20000000

    a = -20000000/2 = -10000000 m/sec²

   so force = mass × acceleration

                   = 10/1000 × -10000000 = 100000 N

now, by defination of acceleration

a = v-u/t

-10000000 = 0 - 1000/t

t = -1000/-10000000 = 0.0001 sec

hope it helps you very well