It is easier to roll a barrel full of coal tar than to pull it because
Options: the full weight of the barrel comes into play when it is pulled, the rolling friction is much less than the sliding friction, more surface area of the barrel is in contact with the road when it is pulled, coal tar is a liquid and it flows in the barrel when it is rolled
Options: the pressure is the same as that outside, normal atmospheric pressure is maintained by the use of air pumps, the pressure inside is less than the pressure outside, normal humidity and partial vacuum are maintained
Sound produced at a point is heard by a person after 5 second, while the same sound is heard by another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and minimum distances between the two persons?
Options: 1.8 km, 0.15 km, 2.2 km, 0.20 km, 2.8 km, 0.25 km, 3.3 km, 0.30 km