The critical f value with 8 numerator and 29 denominate degr

The critical f value with 8 numerator and 29 denominate degree of free at a=0.01 15 2.28 3.20 3.3.33 3.64

Solution

The work done by gravity during decent of projectile is positive because the object is going down and the gravity always acts downwards .the force andotion are in same direction.

Therefore work is the integral of dot product of force and vector in the direction of motion. Since both are in same direction work must be positive. i.e option A