Question

A bullet a mass 20g
stationary wooden block s
penetration of bullet into the
y the wooden block on the built​

Answer 1

Answer:

Answer:Given, Mass of bullet, m = 10 g = 10/1000 kg = 0.01 kg

Initial velocity of bullet, u = 150 m/s

Since bullet comes to rest, thus final velocity, v =0

Time, t = 0.03 s

Distance of penetration, i.e. Distance, covered (s)=?

Magnitude of force exerted by wooden block =?

We know that,

v

=

u

+

a

t

v=u+at

⇒

0

=

150

m

s

−

1

+

a

×

0.03

s

⇒0=150ms-1+a×0.03s

⇒

−

150

m

/

s

=

a

×

0.03

s

⇒-150m/s=a×0.03s

⇒

a

=

−

150

m

/

s

0.03

s

=

−

5000

m

s

−

2

⇒a=-150m/s0.03s=-5000ms-2

We know that,

s

=

u

t

+

1

2

a

t

2

s=ut+12at2

⇒

s

=

150

m

/

s

×

0.03

s

⇒s=150m/s×0.03s

+

1

2

(

−

5000

m

s

−

2

)

×

(

0.03

s

)

2

+12(-5000ms-2)×(0.03s)2

⇒

s

=

4.5

m

−

2500

m

s

−

2

×

0.0009

s

2

⇒s=4.5m-2500ms-2×0.0009s2

⇒

s

=

4.5

m

−

2.25

m

⇒s=4.5m-2.25m

⇒

s

=

2.25

m

⇒s=2.25m

Magnitude of force exerted by wooden block

We know that, Force = mass x acceleration

Or,

F

=

0.01

k

g

×

–

5000

m

s

−

2

=

−

50

N

F=0.01kg×–5000ms-2=-50N

Therefore, Penetration of bullet in wooden block = 2.25 m

Force exerted by wooden block on bullet = – 50 N. Here negative sign shows that force is exerted in the opposite direction of bullet.

Answer 2

Answer:

Answer:Given, Mass of bullet, m = 10 g = 10/1000 kg = 0.01 kg

Initial velocity of bullet, u = 150 m/s

Since bullet comes to rest, thus final velocity, v =0

Time, t = 0.03 s

Distance of penetration, i.e. Distance, covered (s)=?

Magnitude of force exerted by wooden block =?

We know that,

v

=

u

+

a

t

v=u+at

⇒

0

=

150

m

s

−

1

+

a

×

0.03

s

⇒0=150ms-1+a×0.03s

⇒

−

150

m

/

s

=

a

×

0.03

s

⇒-150m/s=a×0.03s

⇒

a

=

−

150

m

/

s

0.03

s

=

−

5000

m

s

−

2

⇒a=-150m/s0.03s=-5000ms-2

We know that,

s

=

u

t

+

1

2

a

t

2

s=ut+12at2

⇒

s

=

150

m

/

s

×

0.03

s

⇒s=150m/s×0.03s

+

1

2

(

−

5000

m

s

−

2

)

×

(

0.03

s

)

2

+12(-5000ms-2)×(0.03s)2

⇒

s

=

4.5

m

−

2500

m

s

−

2

×

0.0009

s

2

⇒s=4.5m-2500ms-2×0.0009s2

⇒

s

=

4.5

m

−

2.25

m

⇒s=4.5m-2.25m

⇒

s

=

2.25

m

⇒s=2.25m

Magnitude of force exerted by wooden block

We know that, Force = mass x acceleration

Or,

F

=

0.01

k

g

×

–

5000

m

s

−

2

=

−

50

N

F=0.01kg×–5000ms-2=-50N

Therefore, Penetration of bullet in wooden block = 2.25 m

Force exerted by wooden block on bullet = – 50 N. Here negative sign shows that force is exerted in the opposite direction of bullet.