Question
A boy goes to school with a speed of 85 km/h and comes
back with a speed of 40 km/h. find his average speed?Solution
Since the distance travelled by a boy (going to school and coming back from school) is equal. So, average speed = 2xy/(x + y) Average speed = (2 x 85 x 40)/(85 + 40) Average speed = (2 x 85 x 40)/125 = 54.4 km/hr
A body is said to be in equilibrium when:
Which polymer is used in the production of bullet-proof materials?
Which one among the following statements is not true for Mammals?
Which of the following is a chemical change?
Which vitamin is also known as Vitamin-B2?
If the root mean square speed of gas molecules is doubled, the absolute temperature of the gas:
Which vitamin helps in improving night vision?
Which vitamin is essential for RBC formation?
Which of the following statements for the given chemical reaction is true?
Fe₂ O₃ + 2Al → Al₂ O₃  + 2Fe
The force which opposes the relative motion between different layers of liquid or gases is called –
