The horizontal component of acceleration, ay during a projectile motion is usually assumed to a)-9.81 m/s^2 b)-zero c)- constant d)- 32.2 m/s^2

b) zero

Explanation:

The horizontal component of acceleration during projectile motion is usually assumed to be zero.Because in projectile motion horizontal component of velocity will remain the constant and we know that rate of change of velocity with time is called acceleration.So when velocity is constant then acceleration will be zero.

In projectile motion ,gravitational acceleration will be in only vertical direction.

this is true

explanation:

i looked it up