The density of water is 1000 kg m^3. What is the value expressed in gcm^-3 units? please help me.. (1) 1000 (2) 100 (3) 1 (4) 0.1 (5) 0.01

Here's the neat, cool way to convert units like this:

-- 1 kilogram  =  1,000 grams

-- 1 meter  =  100 centimeters

So . . . . .

(1000 kg/m³) x (1000 g/kg) x (1 m/100 cm)³ =

(1,000 kg/m³) x (1,000 g/kg) x (1 m³/1,000,000 cm³) =

(1,000 x 1,000 x 1 / 1,000,000) (kg-g-m³ / m³-kg-cm³)  =  1 g/cm³

the assestment will probley apele with cause and effect

there are no contact forces mentioned on the list of choices that you've provided.