The property that compares the mass of an object with its volume is density.
I’m almost 100 percent sure it’s the first one
The range of a projectile can be found directly using:
R = (v²sin2∅) / g
v = √((98 x 9.81)/(sin(90)))
v = 31.0 m/s
That's true.
Netwon's second law states that the resultant of the forces F acting on a body is equal to the product between its mass m and its acceleration a:
![\sum F = ma](https://tex.z-dn.net/?f=%5Csum%20F%20%3D%20ma)
This means that if the net force acting on an object is different from zero (term on the left), than the acceleration of the object (term on the right) must be different from zero as well, and therefore the body is accelerating.
In particular, both F and a in the equation are vectors: this means that if the acceleration is positive, F and a have the same direction. In this problem, the acceleration is positive (because the object is speeding up), therefore the force and the acceleration have same direction.