Question
A boat can cover 36 km in still water and 45 km in
downstream in 4 hours and 3 hours respectively. Find the time taken by the boat to cover 60 km upstream and 27 km downstream.Solution
Speed of the boat in still water = 36/4 = 9 km/h Downstream speed of the boat = 45/3 = 15 km/h Speed of the stream = 15 – 9 = 6 km/h Upstream speed of the boat = 9 – 6 = 3 km/h Time taken to cover 60 km upstream and 27 km downstream = 60/3 + 27/15 = 20 + 1.8 = 21.8 hours
Which of the following is Vitamin-E?
In Young’s double-slit experiment, dark fringes on the screen occur where:
Which one of the following statement regarding the sun is correct?Â
A body of mass 2 kg is moving in SHM with angular frequency 4 rad/s and amplitude 0.1 m. Max kinetic energy is:
Natural radioactivity was discovered byÂ
Which metal is the best conductor of electricity?
Zero group was introduced by
When milk is churned, the cream separates from it clue to:
The Periodic Law stating that ‘the properties of elements are the periodic function of their atomic masses’ was given by
A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole?
Relevant for Exams:
