Mathematics and Physics Division College Physics I-PHY 101 Test 4 pts.) Each of
ID: 1793804 • Letter: M
Question
Mathematics and Physics Division College Physics I-PHY 101 Test 4 pts.) Each of the following questions is worth I point Can the kinetic energy of an object be negative? a) b) A. Yes No B. Can the gravitational potential energy of an object be negative? a) b) Yes No C. Is mechanical energy conserved when there is friction? a) b) Yes No If there is no external force on a system of particles, is the total momentum of system conserved? a) Yes b) D. E. Is linear momentum conserved in a collision? Yes a) b) No F Is kinetic energy conserved in an elasic ollson? Yes No a) b)Explanation / Answer
A) (b) NO,
KE = ½mv2 ; since mass can't be negative and speed also can't be negative so KE also can't be negative.
B) (a) YES,
Gravitational Potential energy depends upon the reference level what we consider so it can be negative.
C) (a) NO,
mechanical energy will decrease in presence of Non Conservative force, and Friction is a non conservative force.
D) (a) YES,
Because Force is defined as rate of change of linear momentum, so If there is no external force acting on the system then linear momentum of the system remains conserved.
E) (a) YES,
in a collision in absence of external force Linear Momentum remains conserved.
F) (a) YES,
In elastic collision there is no loss in kinetic energy after the collision.