Question #ee7c8

1 Answer
Nov 7, 2016

Answer:

#E_a=4E_b#

Explanation:

#v_b:"velocity of object before " v_b=v#

#v_a:"velocity of object after "v_a=2v#

#m:"mass of object"#

#E_b:"Kinetic energy of object before "E_b=1/2*m*v_b^2#

#E_a:"Kinetic energy of object after "E_a=1/2*m*v_a^2#

#(E_b)/(E_a)=(cancel(1/2*m)*v_b^2)/(cancel(1/2*m)*v_a^2)#

#"So "v_b=v ; v_a=2v#

#(E_b)/(E_a)=(v^2)/(2v)^2#

#(E_b)/(E_a)=cancel(v^2)/(4cancel(v^2))#

#(E_b)/(E_a)=1/4#

#E_a=4E_b#