Question
A soap bubble expands isothermally and its radius
doubles. The work done by surface tension during this expansion is:ÂSolution
When a soap bubble expands, work is done against surface tension to increase the surface area. A soap bubble has two surfaces (inner and outer), so total surface area is twice that of a single sphere. Let:
- Initial radius =
- Final radius = 2R
- Surface tension = T
Car' A' travels at the speed of 65 km/hr and reaches its destination in 8 hours. Car 'B' travels at the speed of 70 km/hr and reaches its destination in...
A car travels at a speed of 90 km/h and takes 4.5 hours to cover a specific distance. A train can cover the same distance in 3 hours. If the speed of th...
Arjun, Bheem and Nakul walk at speeds in the ratio 3:2:1. If Nakul takes 60 minutes to reach a temple, calculate how much time Arjun would take to reach...
Speed of a car is 150% more than that of a bus. Find the distance traveled by the bus in 6 hours 30 minutes if the time taken by the car to cover 960 km...
A car is traveling at a speed of 144 km/hr. The car's tires have a diameter of 70 m. How long will it take for the car to complete 12 revolutions of its...
A bus was travelling from Jaipur to Udaipur was delayed by 15 minutes and made up for the delay on a section of 85 km travelling with a speed 12 km per ...
‘A’ and ‘B’ started moving towards each other at same time with a speed of 23 km/hr and 24 km/hr, respectively. If the distance covered by ‘A�...
The speed of a bike increases by 4 km/hr after every 1 hour. If the distance travelled by the bike in 1st hour is 20 km, the find the total distance tra...
While going to a destination after travelling 75km, the driver noticed some problem in the clutch of the bus due to which he had to proceed at 2/5 of it...
A boy goes to school with a speed of 80 km/h and comes back with a speed of 45 km/h. find his average speed?
Relevant for Exams:
