Answer:
360N
Explanation:
The frictional force = centripetal force = mass * centripetal acceleration = ma
Since centripetal acceleration = V^2/ r
Frictional force = mv^2 / r
Substitute the values of m = 80kg, radius = 2m and tangential speed = 3m/s
Frictional force = 80 * (3)^2/ 2 = 360N
Explanation:
In physical sciences, mechanical energy is the sum of potential energy and kinetic energy. It is the macroscopic energy associated with a system. The principle of conservation of mechanical energy states that if an isolated system is subject only to conservative forces, then the mechanical energy is constant. If an object moves in the opposite direction of a conservative net force, the potential energy will increase; and if the speed (not the velocity) of the object changes, the kinetic energy of the object also changes. In all real systems, however, nonconservative forces, such as frictional forces, will be present, but if they are of negligible magnitude, the mechanical energy changes little and its conservation is a useful approximation. In elastic collisions, the kinetic energy is conserved, but in inelastic collisions some mechanical energy may be converted into thermal energy. The equivalence between lost mechanical energy (dissipation) and an increase in temperature was discovered by James Prescott Joule.
Let north as positive
Fnet=10n-5n
=5n north
Answer:
The magnification is 
Explanation:
From the question we are told that
The power of the lens is 
Generally 
The object distance is
the negative sign is because the distance is measured in the opposite direction of incident light (i.e away )
Generally the focal length is mathematically represented as
=>
=> 
converting to cm
=> 
Generally from lens equation we have that

=> 
=> 
Generally the magnification is mathematically represented as

=> 
=> 