A woman uses a single fixed pulley to lift a bucket of water from a well. The bucket and water together weigh 250N but the woman has to apply an effort of 300N to lift the bucket. Calculate the mechanical advantage of the set-up.
- Animal bones
- Tea leaves
What makes plastics non-biodegradable?
Plastics require high temperature to degrade.
Plastics cannot be decomposed by microbes.
Plastics have a lot of carbon in it.
Plastics have organic additives in it.
Assertion: Plastic bags remain as harmful substances in both soil and water.
Reason: Soil microflora lacks bio-catalysts for rendering plastics harmless.
Both A and R are true
A is false, R is true
A is true and R is false
Both A and R are false
Nowadays, the usage of bioplastics is promoted more than ordinary plastics because:
All bioplastics are biodegradable or compostable.
Compostable products can be turned into compost within six months.
All the above options are correct.
Bioplastics break down under the influence of natural elements.
Select the group of different substances that make soil rich in nutrients.
Polethlene bags, crokery items and softdrink tins.
Kitchen waste, leaves and fruit peels.
Wrappers of chips, waste CDs and unused batteries.
Urea, DDT and compost.
Which of the following components of municipal solid wastes can be recycled?
Paper and paper products
- All of the above.
Which among the following pictures are biodegradable substances?
1 and 2