Question

A bullet of mass 200g. Hits a block of thickness 6 cm with a speed of 100mper second .It emerges with 10% of its initial KE .find the emergent speed

Answer 1

Answer:

31.622

Explanation:

Given A bullet of mass 200 g. Hits a block of thickness 6 cm with a speed of 100 m per second .It emerges with 10% of its initial K E .find the emergent speed

We know that  

Kinetic energy = 1/2 m v^2

According to question the bullet emerges with 10% of its initial kinetic energy.

So 10 / 100 x 1/2  mv^2 = 1/2 mv^2

  0.1 x 1/2 m u^2 = 1/2  mv^2

      0.1 u^2 = v^2

       0.1 x 100^2 = v^2

So v = √ 0.1 x 100^2

      v = √1000

          = 10 √10 m/s

        So v = 31.622 m/s

Answer 2

Answer:

speed is 31.62 m/s

Explanation:

first we have to find intital ke and then with help of answer we have to find 10 % and then mass is constant the energy is 100J so by puting the value we get v 31.62 m/s