Question

You have been asked to design a "ballistic spring system" to measure the speed of bullets. A bullet of mass mmm is fired into a block of mass MMM. The block, with the embedded bullet, then slides across a frictionless table and collides with a horizontal spring whose spring constant is k. The opposite end of the spring is anchored to a wall. The spring's maximum compression d is measured.

What was the speed of a 1.8 gg bullet if the block's mass is 1.2 kg and if the spring, with k = 37 N/mN/m , was compressed by 14 cm ?

What percentage of the bullet's energy is "lost"?

Answer #1

Mass of the bullet, m = 0.0018 kg

Mass of the block. M = 1.2 kg

Spring constant, k = 37 N/m

Compression of the spring, x = 0.14 m

Work done to compress the spring, W
= ½ k x^{2} = ½ x 37 x 0.14 x 0.14= 0.3626 J

Energy of the bullet block system,
E = ½ (m+M) V^{2}

Work done to compress the spring is provided by the energy of bullet block system.

½ (m+M) V^{2} =
0.3626

½ x (0.0018 + 1.2 ) V^{2} =
0.3626

The common velocity of bullet block, V = 0.777 m/s

Using law of conservation,

mv = (m+M) V

initial speed of the bullet, v
= **(m+M) V/m
=** ( 0.0018 + 1.2 ) x
0.777/0.0018 = 518.7 m/s

**speed of bullet, v = 518 .7
m/s**

energy of bullet before hitting the
block, K1 = 1/2mv^{2} = ½ x 0.0018 x 518.7^{2} =
1076.2 J

energy of bullet after hitting the
block, K2 = 1/2mV^{2} = ½ x 0.0018 x 0.777^{2} =
0.00054 J

percent loss of energy of the bullet =(K2 – K1) x100/K1= (0.00054 – 1076.2) x 100/1076= - 610 %

You have been asked to design a "ballistic spring system" to
measure the speed of bullets. A bullet of mass m is fired
into a block of mass M. The block, with the embedded
bullet, then slides across a frictionless table and collides with a
horizontal spring whose spring constant is k. The opposite
end of the spring is anchored to a wall. The spring's maximum
compression d is measured.
*I just need help with Part C the other parts...

A 12.0g bullet is fired horizontally into a 650g block that is
initially at rest on a frictionless horizontal surface. The initial
velocity of the bullet is 450m/s. After the bullet is embedded into
the block, the bullet-block system slides along the frictionless
surface into a spring having spring constant k=470N/m
a. What is the speed of the block after the bullet once it’s
stuck in the block
b. What was the work done on the bullet during the collision...

10. A bullet of mass M1= 0.4 Kg
moving with initial velocity V1i= 800
m/s gets embedded into a block of wood of mass
M2= 3.6 Kg that was initially at rest
(V2i=0). The block is attached to a
spring having spring constant K=400 N/m. After
making the inelastic collision, the bullet-block
combination slides on a horizontal frictioless surface and
compresses the spring.
Part A
The amount of compression distance delta
X by which the spring gets compressed by the bullet-block...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 16 minutes ago

asked 17 minutes ago

asked 23 minutes ago

asked 36 minutes ago

asked 40 minutes ago

asked 55 minutes ago

asked 56 minutes ago

asked 58 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago