Question
On a circular racetrack that measures 4,000 meters in
circumference, Kia and Sia begin a race at the same point and at the same time, traveling at speeds of 90 km/h and 18 km/h, respectively. If the race continues for 40 minutes, how many times will Kia and Sia meet again at the starting point?Solution
Speed of Kia = 90 X (5/18) = 25 m/s Speed of Sia = 18 X (5/18) = 10 m/s Time taken by Kia to complete one round = (4,000/25) = 160 seconds Time taken by Sia to complete one round = (4,000/10) = 400 seconds Time after which both of them will meet at the same starting point = LCM of 160 and 400 = 800 seconds Therefore, number of times they meet in 40 minutes = (40 X 60) ÷ 800 = 3
What is the name of the protein digesting enzyme released by the gastric glands?
The method of protecting iron from rusting, by coating a thin layer of Zinc is called -
Which of the following devices stores electrical energy in a magnetic field?
Which one of the following wave- lengths of light is most effective in photosynthesis?
What is the work to be done to increase the velocity of a car from 30 km h⁻¹ to 60 km h⁻¹ if the mass of the car is 1500 kg?
Which of the following is a 'Universal Blood Recipient' group?
Which part of cinnamon tree is used in condiments and medicines ?
The anther contains
Which of the following statements for the given chemical reaction is true?
Fe₂ O₃ + 2Al → Al₂ O₃ + 2Fe
What is the function of the red blood cells?