1) A railroad car of mass 2.46 * 10 4 kg, ismoving with a speed of 4.11 m/s. It
ID: 1681674 • Letter: 1
Question
1) A railroad car of mass 2.46 * 104 kg, ismoving with a speed of 4.11 m/s. It collides and couples with threeother coupled railroad cars, each of the same mass as the singlecar and moving in the same direction with an initial speed of 2.06m/s. (a) What is the speed of the four cars afterthe collision?m/s ----------- i alreadygot this one correct
(b) How much energy is transformed into internal energy in thecollision? ____________ kJ note- incorrect answers i have already triedinclude: 29651.77 and 30 and 2.965 and 29.65 2) A 56.0 kg boy and his 45.0 kg sister, both wearing rollerblades face each other at rest. The girl pushes the boy hard,sending him backward with a velocity 3.20 m/s toward the west.Ignore friction. How much chemical energy is converted intomechanical energy in the girl's muscles?
___________ J
note- incorrect answers i have already tried include: 786 and 356.8 (a) What is the speed of the four cars afterthe collision?
m/s ----------- i alreadygot this one correct
(b) How much energy is transformed into internal energy in thecollision? ____________ kJ note- incorrect answers i have already triedinclude: 29651.77 and 30 and 2.965 and 29.65 2) A 56.0 kg boy and his 45.0 kg sister, both wearing rollerblades face each other at rest. The girl pushes the boy hard,sending him backward with a velocity 3.20 m/s toward the west.Ignore friction. How much chemical energy is converted intomechanical energy in the girl's muscles?
___________ J
note- incorrect answers i have already tried include: 786 and 356.8 2) A 56.0 kg boy and his 45.0 kg sister, both wearing rollerblades face each other at rest. The girl pushes the boy hard,sending him backward with a velocity 3.20 m/s toward the west.Ignore friction. How much chemical energy is converted intomechanical energy in the girl's muscles?
___________ J
note- incorrect answers i have already tried include: 786 and 356.8
Explanation / Answer
Given that the massof car is m = 2.46*104 kg Initial speed is u1= 4.11 m/s Initial speed ofother cars is u2 = 2.06 m/s Final speed v =2.57m/s------------------------------------------------------------------------------- Theenergy lossed during collision is K =(1/2)m*u12 +(1/2)3m*u22 -(1/2)4m*v2 =39400.59J=39.4 KJ
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.