49. A 6.1-kg bowling ball is liſted 2.1 m to a shell. Find the increase in the ball-Farth system's energy.

125.5J

Explanation:

Given parameters:

Mass of the bowling ball  = 6.1kg

Height of lifting  = 2.1m

Unknown:

Increase in the ball energy  = ?

Solution:

The ball has changed position by moving it from one point to another. So, it has acquired more potential energy.

 Potential energy  = mgh

     m is the mass

     g is the gravity  

     h is the height

Now insert the given parameters and solve;

       Potential energy  = 6.1 x 9.8 x 2.1  = 125.5J

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.