Answer:
TO MEASURE THE ANGLES OF RAYS
Explanation:
I believe it would be a musical note
Answer:
V=15.3 m/s
Explanation:
To solve this problem, we have to use the energy conservation theorem:

the elastic potencial energy is given by:

The work is defined as:

this work is negative because is opposite to the movement.
The gravitational potencial energy at 2.5 m aboves is given by:

the gravitational potential energy at the ground and the kinetic energy at the begining are 0.

Answer:
Explanation:
1) Force Friction = Normal Force * Coefficient of Friction
Force Friction = Mass * Gravity * Coefficient of Friction
2) F = ma
Force = mass * acceleration
Force Friction (from #1) = mass * acceleration
acceleration = Force Friction / Mass