Acar goes from 80 km/h to 20 km/h in 0.5 h. what is the acceleration in km/h squared?

In physics, acceleration is defined as the rate of change of the velocity of an object with respect to time. That is A = VF - VI /T;

Where A =  Acceleration

VF = Final velocity = 20 km

VI = Initial velocity = 80 km

T= Time = 0.5 hr

A = (20 - 80)/ 0.5 = - 60/.5

A = - 120 Km/ hr^2

Therefore, the acceleration of the car is -120 km/hr^2.

Because the value is negative, the appropriate name that describe it is deceleration.

it would be kevlar ^^