Assume: the bullet penetrates into the block

and stops due to its friction with the block.

the compound system of the block plus the

bullet rises to a height of 0.13 m along a

circular arc with a 0.23 m radius.

assume: the entire track is frictionless.

a bullet with a m1 = 30 g mass is fired

horizontally into a block of wood with m2 =

4.2 kg mass.

the acceleration of gravity is 9.8 m/s2 .

calculate the total energy of the composite

system at any time after the collision.

answer in units of j.

taking the same parameter values as those in

part 1, determine the initial velocity of the

bullet.

answer in units of m/s.

To solve this problem we will start considering the total energy of the system, which is given by gravitational potential energy of the total of the masses. So after the collision the system will have an energy equivalent to,

Here,

= mass of bullet

= Mass of Block of wood

The ascended height is 0.13m, so then we will have to

PART A)

PART B) At the same time the speed can be calculated through the concept provided by the conservation of momentum.

Since the mass at the end of the impact becomes only one in the system, and the mass of the block has no initial velocity, the equation can be written as

The final velocity can be calculated through the expression of kinetic energy, so

Using this value at the first equation we have that,

answer: a. same unit

explanation:

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