An electric heater of 1000w is used for 2 hours a day. what is the cost for using in for a month of 28 days, if 1 unit costs 3.00 rupees.

Explanation:

total consumption in a month - 1000×2×28= 56000 w-hrs

1 unit = 1Kwh

total unit in month = 56000/1000 = 56

total cost = 56×3 = 168 rs

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.

b. a lightning bug, plug of grass, and a worm