Blocks A (mass 4.00 kg ) and B (mass 6.00 kg ) move on a frictionless, horizontal surface. Initially, block B is at rest and block A is moving toward it at 5.00 m/s . The blocks are equipped with ideal spring bumpers. The collision is head-on, so all motion before and after the collision is along a straight line. Let x be the direction of the initial motion of block Find the maximum energy stored in the spring bumpers. Find the velocity of block A when the energy stored in the spring bumpers is maximum. Find the velocity of block B when the energy stored in the spring bumpers is maximum. Find the velocity of block A after they have moved apart. Find the velocity of B after they have moved apart.

Answer and Explanation:

mass of the bock A is, m1=4 kg

mass of the bock B is, m2=6 kg

velocity of the block A is u1=5 m/sec

velocity of the block B is u2=0

a)

by using law of conservation of energy,

m1*u1+m2*u2=(m1+m2)*v

4*5+0=(4+6)*v

final velocity v=2 m/sec ( when the spring gets compression)

by using law of conservatio of enegry,

maximum energy stored U=K1-K2

U=1/2*m1*u1^2-1/2*(m1+m2)v^2

U=1/2*4*5^2-1/2*(4+6)*2^2

U=30 J

b)

if energy stored in the bumper is maximum,

velocity of block A is, v=2 m/sec

velocity of block B is, v=2 m/sec

c)

after moving back,

velocity of the block A is,

v1=((m1-m2)/(m1+m2))*u1

v1=((4-6)/(4+6))*5

v1=-1 m/sec

and

velocity of the block B is,

v2=((2*m1)/(m1+m2))*u1

v2=((2*4)/(4+6))*5

v2=4 m/sec

nec chapter 5 contains

c. information on special occupancy areas

nec chapter 6 covers

a. special equipment

which of the following rules contain the words shall or shall not and must be adhered to?

b. mandatory rules

which of the following rules identify actions that are allowed but not required and typically cover options or alternative methods?

c. optional rules

which of the following serves as the introduction to the nec and provides an overview of the book?

a. nec article 90

organizations that test products for safety are

c. nrtls

the nec is published by the

a national fire protection association

the nec is divided into

b. 9 chapters

the nec provides informative annexes for

c. informational materials and examples

two terms from nec article 100 that trainees should become familiar with are

b. labeled and listed

explanation: