What is the nature of velocity-time graph for a car moving with uniform acceleration?

The area under the velocity-time graph for a particle moving in a straight line with uniform acceleration gives

A car undergoes a uniform circular motion. The acceleration of the car is

The direction of acceleration in uniform circular motion is along the

A bus starting from a bus-stand and moving with uniform acceleration attains a speed of 20 km/h in 10 minutes. What is its acceleration?

At uniform speed the acceleration is