Question

b) An echo is returned in 3s. What is the distance of reliecuing surlace from the source?
( speed of sound=342m/s)
13. a) Find the energy in kWh consumed in 10 hrs by four devices of power 500W each.(1)​

Answer 1

Explanation:

time taken to hit surface is 3/2 = 1,5

speed equals distance/time

342 = x/1.5

x = 342 × 1.5

distance = 513m

Answer 2

Answer:

13. given:

time= 10 hrs

power of 1 device= 500W

= 0.5KW

ENERGY= POWER* TIME

= 0.5*10

= 5KWH

So, energy consumed by 4 devices=5*4

=20units