She can first measure the mass on the scale, then measure the cm^3 by putting water in the cylinder and measuring the original water level minus the water level after you put the rock in. The take the measurement from the scale (g) and divide it by the measurement in the graduated cylinder (c^3).
To solve this problem it is only necessary to apply the kinematic equations of angular motion description, for this purpose we know by definition that,

Where,
Angular Displacement
Angular Acceleration
Angular velocity
Initial angular displacement
For this case we have neither angular velocity nor initial angular displacement, then

Re-arrange for 

Replacing our values,


Therefore the ANgular acceleration of the mass is 
Answer:
C. At the instant the ball reaches its highest point.
Explanation:
When a body is thrown up, it tends to come down due to the influence of gravitational force acting on the body. The body will be momentarily at rest at its maximum point before falling. At this maximum point, the velocity of the body is zero and since force acting on a body is product of the mass and its acceleration, the force acting on the body at that point will be "zero"
Remember, F = ma = m(v/t)
Since v = 0 at maximum height
F = m(0/t)
F = 0N
This shows that the force acting on the body is zero at the maximum height.
According to newton's third law of motion, when a hammer strikes and exerts force to push it into a piece of wood, the nail <span>C. exerts an equal or opposite force on the hammer. The third law of motion states that every action has an equal BUT opposite reaction. This means that the nail exerts the same force the hammer exerts on it.</span>
it's how much it weighs and how much force is pushing on it like a egg if i drop it the weigh can cause it to break and how much force the gravity is pushing on it.