The Hindu (Kolkata)

The highs and lows of the forces around us

- Vasudevan Mukunth

Possibly the weakest (non-zero) estimate of a force is the gravitatio­nal force between one proton and one electron in a ________ ____. Fill in the blanks.

This weapon, invented in the 1970s and today used by police forces around the world, when detonated produces bright light and 1.6–8 kilonewton­s per square meter of sound pressure, sometimes enough to cause permanent hearing loss. Name it.

Scientists have estimated that the sunlight incident on the earth exerts a collective force of 570 million newtons. The resulting pressure on the planet is called the radiation pressure. Some spacecraft are fitted with _____ _____ that use radiation pressure from the sun to move in orbit or space. Fill in the blanks.

In 2019, the SI units were redefined to be determined using only the fundamenta­l constants. Before this, however, the SI unit of _______ was defined as the amount flowing between two parallel conductors held a metre apart and such that they exerted a force on each other of 0.0000002 newtons per metre. Fill in the blank.

Eight-thousand newton -- this is roughly the amount of force weight lifters achieve during a _____ and ____ lift. Fill in the blanks.

Answers to April 4 quiz:

1. Lowest temperatur­e to which a surface can be evaporativ­ely cooled – Ans: Wet-bulb temperatur­e

2. Thermomete­r reading when exposed to sunlight – Ans: Dry-bulb temperatur­e

3. Air’s capacity for moisture adjusted for temperatur­e – Ans: Relative humidity

4. Temperatur­e at which air is 100% saturated with moisture –

Ans: Dew point

5. Index that denotes harm caused by sunlight – Ans:

Ultraviole­t index

Visual: La Niña

First contact: Nishant Kumar | K.N. Viswanatha­n

Answers to April 5 quiz:

1. Protein fibres in skin that break down over time, resulting in wrinkles – Ans: Collagen

2. Term for age-related condition characteri­sed by decrease in brain volume, cognitive function – Ans: Brain atrophy

3. Hormone produced less with age, leading to fatigue and weight gain – Ans: Testostero­ne

4. Vitamin associated with healthy skin, vision, immune function –

Ans: Vitamin E

5. Mineral associated with brain health, contribute­s to oxidative stress when in excess – Ans: Calcium

Visual: Telomeres

First contact: K.N. Viswanatha­n

Newspapers in English

Newspapers from India