Answer:
Explanation:
The hand provides Kinetic Energy in moving.
The KE is transformed to Frictional energy
The Frictional Energy can produce heat and light energy.
The sandpaper produces little shreds from the grit of the paper.
The shreds have KE (they move)
Answer:
The force of gravity exerts a downward force. The floor exerts an upward force. Since these two forces are of equal magnitude and in opposite directions, they balance each other.
Answer:

Explanation:
For the simple pendulum problem we need to remember that:
,
where
is the angular position, t is time, g is the gravity, and L is the length of the pendulum. We also need to remember that there is a relationship between the angular frequency and the length of the pendulum:
,
where
is the angular frequency.
There is also an equation that relates the oscillation period and the angular frequeny:
,
where T is the oscillation period. Now, we can easily solve for L:

Explanation:
S =ut + 1/2at^2
S = 0×6.5 + (1/2 × 9.54) × 6.5^2
S =0 + 4.77 ×42.25
S=201.5m