Question
What is the speed of the stream if a ship takes 15 hours
to travel 240 km in calm waters, given that the ratio of its speed against the current to its speed with the current is 5:11, respectively?Solution
ATQ, Let the upstream speed of the ship be '5a' km/h So, downstream speed of the Ship = 5a × (11/5) = '11a' km/h So, speed of the Ship in still water = 240 ÷ 15 = 16 km/h Let the speed of the stream be 'b' km/h ATQ; 5a + b = 11a - b Or, 2b = 6a So, b = 3a So, speed of the boat in still water = 11a - 3a Or, 16 = 8a So, a = 2 So, speed of the stream = 3a = 2 × 3 = 6 km/h
A car increases its speed from 20 m/s to 60 m/s in 8 seconds. Find its acceleration. Â
A wire is stretched by a force such that it experiences a strain of 2 x 10-3. If Young’s modulus of the material is 2 x 1011 Pa,...
When an electric current flows, electrons move from:
Two point charges +q and −q are separated by a distance 2a. The electric field at a point on the perpendicular bisector at distance r from center is p...
What is the effect of a magnetic field on a current carrying conductor? Â
If n resistors with R Ω each as resistance are connected in parallel, then the equivalent resistance of the network is:
The electric and magnetic fields of an electromagnetic wave are _____________
The surface tension of water on adding detergent to it –
A machine does 600 J of work in 2 minutes. Find its power. Â
The phenomenon of interference is based on the principle of:
Relevant for Exams:
