What is retardation?

A car moving with a speed of 126 kmh^-1 is brought to stop within a distance of 200 m. What is its retardation and how long it takes for the car to stop ?

A car moving along a straight highway with a speed of 126 km h^-1 is brought to a stop within a distance of 200 m. What is the retardation of the car (assumed uniform), and how long does it take for the car to stop?

The initial velocity of a particle moving along straight line is 20 m/s and its retardation Is 2 m/s_2. The distance moved by the particle in the fifth sec. of its motion is :

What is radius ratio? What is its significance in case of ionic crystal?

What is edema?

What is hydrogenation ? What is its industrial application?

What is an ore?

What is ppm?

Give one example of retardation.