acceleration

noun
1
an increase in how fast something happens
شتاب, تسریع, افزایش سرعت
2
the rate at which a vehicle increases speed
شتاب, افزایش سرعت, شتاب‌گیری
a car with good acceleration
acceleration from 0–60 mph in 11.2 seconds
This model has the best acceleration of any available sports car.
3
the rate at which the velocity(= speed in a particular direction) of an object changes
شتاب
acceleration caused by gravity