A bus starts with 40 km/hr speed on a straight road, after 15 seconds, its velocity becomes 100 km/hr. what is the average speed of its motion and also find the acceleration of the bus during this time interval?
The time period of a simple pendulum of length 80 cm is 2 sec. what is the new time period of a pendulum if (i) its length becomes 320 cm, (ii) g becomes g/4, (iii) length becomes 20 cm?