Tag: science & technology

Orbiting spacecraft are in continuous free fall toward Earth, but their forward velocity prevents them from hitting the ground - they keep missing it as they fall. This creates the apparent weightlessness. Microgravity is the result, not the cause. Frictionless glide is incorrect in atmosphere; counter thrust is meaningless.

Speed is distance per time (scalar), while velocity is displacement per time (vector). Similarly, distance is a scalar quantity measuring path length, while displacement is a vector measuring straight-line change in position. The analogy holds: scalar : vector :: scalar : vector. The other options are unrelated concepts.

Work is defined as force multiplied by displacement in the direction of the force. Since the carpenter holds the drywall stationary, there is no displacement, so the work done is zero joules. The time spent holding and the weight of the object don't matter when nothing moves.

Both vehicles have the same momentum: p = mv = 1000 × 40 = 40,000 kg·m/s for the VW and p = 4000 × 10 = 40,000 kg·m/s for the Explorer. However, kinetic energy depends on velocity squared (KE = 1/2 mv²). The VW has 800,000 J while the Explorer has only 200,000 J, so the VW has much more kinetic energy despite equal momentum.

The pendulum bob's speed at the bottom is given by v = sqrt(2gh). When the height is quadrupled, the speed only doubles (sqrt(4) = 2). In a perfectly elastic collision between objects of equal mass, the bob transfers all its velocity to the block, so the block's initial speed becomes twice as fast.

At maximum height, the rock's final velocity is zero. Using the kinematic equation v² = u² + 2as where v = 0, u = 30 m/s, and a = -9.8 m/s² (downward), we solve for height: 0 = 30² + 2(-9.8)h, giving h = 900/19.6 ≈ 45.9 meters, which rounds to approximately 45 meters.

Jatinder Kumar Bajaj was indeed the first Indian to reach the South Pole, accomplishing this feat in 1989 as part of an international expedition. Rakesh Sharma was the first Indian in space (1984), not the South Pole. Sam Manekshaw was a renowned military commander, not an explorer. Shyamchi Aai is a literary work, not a person associated with polar exploration.

Indira Gandhi was the first Indian Prime Minister to be voted out of office when she lost the 1977 general election following the Emergency period. The opposition Janata Party coalition defeated her Congress party. This was a historic moment as it was the first time the Congress party lost power at the national level since independence. Saran Singh (Sardar Swaran Singh) was a cabinet minister, not PM. Chandrasekar and Deve Gowda became PM much later.

Durga Agarwal (later known as Kanupriya Agarwal) was India's first test tube baby, born on October 3, 1978 in Kolkata. She was conceived through IVF technology pioneered by Dr. Subhas Mukherjee. The other Agarwal names listed (Preethi, Isha, Asha) are not associated with this historic medical achievement in India.

Lala Amarnath was the first Indian cricketer to score a Test century, achieving this milestone (118 runs) on his debut against England in Mumbai in 1933. This was a historic moment in Indian cricket history. C.K. Nayudu was India's first Test captain but didn't score a century first. Sunil Gavaskar and others came decades later. 'Patoudi' appears to be a misspelling or garbled name.