A parabolic reflector (mirror) transforms an incoming plane wave traveling along the axis into a spherical wave converging toward the focus. Since the principles of reflection are reversible, parabolic reflectors can also be used to project energy of a source at its focus outward in a parallel beam, used in devices such as spotlights and car headlights.
A car covers a certain distance at the speed of 30 km/h and comes back at the speed of 20 km/h. What is the average speed of the car for the entire jour...
The ratio of the speed of two bus P and Q is 4 :7. If P takes 180 minutes more than Q to cover a certain distance, the find then actual time taken by Q ...
A car rental service charges ₹500 for the first 100 kilometers and ₹8 for each additional kilometer. If a customer drives 150 kilometers in a day an...
Train P starts from Lucknow to Dehradun at 11:55 am with an average speed of 30 m/s. Train Q starts from Dehradunto Lucknowat 1:35 pm with an average sp...
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...
‘A’ and ‘B’ started moving towards each other at same time with a speed of 25 km/hr and 15 km/hr, respectively. If the distance covered by ‘Aâ...
Sumit covered a distance of 1000 km in 5 hours on a bike. How much distance will he cover on a bicycle in 7 hours if he rides the bicycle at 2/5th<...
Two trains starts at the same time from Spain and France towards each other with a speed of 160km/hr and 190 km/hr. When they meet, the faster train cov...
In a 1200 m race, bike A beats bike B by 100 m. bike B beats bike C by 100 m in a 600 m race. If bike A beats bike C by 30 sec in a 720 m race, then wha...
A and B are travelling towards each other with a speed of 10 km/hr and 20 km/hr. They started at same time and A covered 15 km less distance than B befo...
