Radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. The sun's rays reach us in the form of electromagnetic radiation. This type of radiation covers a wide spectrum (that is a wide range of frequencies), but those from the sun are mainly infra-red, visible, and ultra-violet.
Speed of a boat in still water is 3 times more than the speed of stream. If boat covers 135 km in downstream in 9 hours, then find the time taken by the...
A man rows a boat a certain distance downstream in 9 hours, while it takes 18 hours to row the same distance upstream. How many hours will it take him t...
The speed of a boat in still water is 12 km/h and the speed of the current is 3 km/h. A person travels 270 kilometers in a boat in the upstream directio...
A boat covers a distance of 108 km downstream in 3 hours. If the ratio of upstream speed to downstream speed of the boat is 5:9, then find the distance ...
A boat covers 35 km downstream in 2 h and covers the same distance upstream in 7 h. Find the speed (in km/h) of the boat in still water.
Sumit can swim 12 km upstream and 16 km downstream in 5 hours. If ratio of speed of stream to that of speed of Sumit in upstream is 1:2, then find the s...
A boat can travel 72 km upstream and 108 km downstream in 5 hours. Find the speed of the boat in still water if the ratio of the ...
Find the total distance covered by boat in each upstream and downstream in 4 hours if the speed of boat in still water and speed of current is 15 km/h a...
"A boat covers 66 km upstream and 98 km downstream in a total of 9 hours. Determine the time required for the boat to travel 48 k...
The sum of the speeds of two boats A and B in still water is 56 km/hr. such that the speed of boat A in still water is 25% less than that of boat B in s...
