4. Dynamics – II

Why a moving bicycle is easier to balance? Relate this to the principles of rotational motion.

A moving bicycle is easier to balance because of angular momentum and gyroscopic stability. As the wheels spin, they create a stabilizing force that resists tipping over. Additionally, steering adjustments help maintain balance, making a moving bicycle more stable than a stationary one. Related Questions: Why door knobs are fixed at the edge of door? … Read more

When standing on a crowded school bus, which stance would provide better stability and prevent you from being pushed over: legs joined or legs spread apart?

Standing with legs spread apart provides better stability on a crowded bus because it increases the base of support and lowers the center of gravity. This helps resist forces from sudden movements or external pushes, preventing loss of balance. Keeping legs together creates a narrow base, making it easier to be pushed over. Related Questions: … Read more

Explain why it’s easier to push a car on flat tyres than inflated ones. What happens to the frictional force between the tyres and the road?

A car on flat tyres is easier to push than one with inflated tyres because flat tyres increase the surface area in contact with the road, reducing the pressure and making it easier to overcome static friction. Inflated tyres have less contact area, leading to a higher normal force and increased friction, making the car … Read more

Why do ice skates effortlessly slide on ice, while your shoes cause skidding?

Ice skates slide effortlessly on ice because the high pressure exerted by the skate blade melts a thin layer of ice, creating a lubricating film of water that reduces friction. Shoes, however, have a larger surface area and higher friction, causing skidding rather than smooth sliding. Related Questions: Why door knobs are fixed at the … Read more

If you drop a feather and a bowling ball from the sane height, which one will reach the terminal velocity first? Which one of them will hit the ground first?

The feather will reach terminal velocity first because it has a higher air resistance relative to its weight, which quickly balances the downward gravitational force. However, the bowling ball will hit the ground first because it experiences less air resistance and continues to accelerate for a longer time before reaching its terminal velocity. Related Questions: … Read more

Why door knobs are fixed at the edge of door? What will happen it the door knob is at the middle of the door?

Door knobs are fixed at the edge of the door to maximize the turning effect (torque) when opening or closing the door. If the knob were placed in the middle, the perpendicular distance from the pivot (hinges) would be reduced, requiring more force to operate the door. This would make opening and closing the door … Read more

Q7. Look at the figure of screw gauge, let a small steel ball is place between its thimble and anvil then:

Look at the figure of the screw gauge, let a small steel ball is place between its thimble and anvil then:         a. What is its main scale reading? b. What is the coinciding division of circular scale? c. Calculate the total diameter of the ball. Ans: a. The main scale reading … Read more

Q6. Look at the measurement of vernier calipers:

Look at the measurement of vernier calipers:             a. What is its main scale reading? b. What is its coinciding division on the vernier scale? Calculate the total reading on the vernier calipers. Ans: a. The main scale reading (reading to which zero of vernier scale coincides) is 2.5 cm. … Read more

Q5. What is pitch and least count of: a. Vernier calipers if the smallest division on the main scale is 1 mm and total divisions on the vernier scale are 20. b. Screw gauge if the smallest division on its main scale is 0.5 mm and its movable scale has 50 divisions.

What is pitch and least count of: a. Vernier calipers if the smallest division on the main scale is 1 mm and total divisions on the vernier scale are 20. b. Screw gauge if the smallest division on its main scale is 0.5 mm and its movable scale has 50 divisions. Ans: a. The least … Read more