Answer:19.5 J
Explanation:
Given
mass of block=3 kg
angular frequency=20 rad/sec
spring constant 
we know total energy remain conserved


Where
=kinetic energy
=potential Energy





When mass reaches amplitude its velocity becomes zero
there is only potential energy which is equal to Total energy

Answer:
write the resistance of one resistor
Explanation:
This is because when resistors are connected in parallel current flows in different directions.