A car is moving along a straight line, say OP in the figure. It moves from O to P in \(18\) s and returns from P to Q in \(6.0\) s. The average velocity and average speed of the car in going from O to P and back to Q respectively are:
1. \(10\) m/s & \(10\) m/s
2. \(20\) m/s & \(30\) m/s
3. \(20\) m/s & \(20\) m/s
4. \(10\) m/s & \(20\) m/s
The position of an object moving along \(x\)-axis is given by \(x=a+bt^2\), where \(a=8.5\) m, \(b=2.5\) and \(t\) is measured in seconds. Its average velocity between \(t=2.0\) s and \(t=4.0\) s is:
1. \(10\) m/s
2. \(15\) m/s
3. \(20\) m/s
4. \(25\) m/s