Question
Two layers of a cloth of equal thickness provide warmer
covering than a single layer of cloth with double the thickness. Why?Solution
Two layers of a cloth are warmer because air trapped between the layers acts as thermal insulator restricting the heat transfer.
- Two bikers, ‘C’ and ‘D’, start from point ‘R’ and ‘S’ respectively towards each other. They meet after 7 hours, and biker ‘D’ has trave...
A coach sees an athlete 85 meters ahead on the track and begins running after him. The athlete is running at a speed of 19 m/sec, while the coach runs a...
On travelling with 45% less speed than his actual speed, Mohan reached the destination 6 hours late. Find the time taken by him to reach his destination...
Arjun, cycling at a speed of 81 km/hr, can complete one round of a square field in 8 seconds. The radius of a circular field is 4 meters more than each ...
A ferry takes 75 minutes to row to place B from another place A along the stream. The distance between place A and place B is 37.5 km. If the speed of t...
Two persons start from the same point at the same time in opposite directions with speeds 5 km/h and 7 km/h. After how many hours will they be 36 km apa...
Vicky and Vikram start running simultaneously around a rectangular track of length 500m from the same point at speeds of 30 km/hr and 20 km/hr. When wil...
Train P starts from Lucknow to Dehradun at 11:55 am with an average speed of 25.5 m/s. Train Q starts from Dehradun to Lucknow at 1:35 pm with an averag...
The ratio of the speed of a car to a bicycle is 4:1 and the bicycle covers 45 km less than the car in the same time interval. If the time taken by the c...
A Truck travel 300 km in 7 hours 30 minutes, if the speed of Bike 20% more than that of Truck, then find the time taken by Bike to travel 720 km.
Relevant for Exams:
