Answer:
t=0.42s
Explanation:
Here you have an inelastic collision. By the conservation of the momentum you have:
m1: mass of the bullet
m2: wooden block mass
v1: velocity of the bullet
v2: velocity of the wooden block
v: velocity of bullet and wooden block after the collision.
By noticing that after the collision, both objects reach the same height from where the wooden block was dropped, you can assume that v is equal to the negative of v2. In other words:
Where you assumed that the negative direction is upward. By replacing and doing v2 the subject of the formula you get:
Now, with this information you can use the equation for the final speed of an accelerated motion and doing t the subject of the formula. IN other words:
hence, the time is t=0.42 s
Answer:
Radio waves
Explanation:
The electromagnetic spectrum includes all different types of waves, which are usually classified depending on their frequency. Ordering them from the highest frequency to the lowest frequency, they are:
- Gamma rays
- X-rays
- Ultraviolet
- Visible light
- Infrared radiation
- Microwaves
- Radio waves
Radio waves are the electromagnetic waves with lowest frequency, their frequency is lower than 300 GHz (
) and therefore they are the electromagnetic waves with lowest energy (in fact, the energy of an electromagnetic wave is proportional to its frequency). They are generally used for radio and telecommunications since this type of waves can travel up to long distances.
Answer:
Position A/Position E
, 
Position B/Position D
, 
, for 
Position C
, 
Explanation:
Let suppose that ball-Earth system represents a conservative system. By Principle of Energy Conservation, total energy (
) is the sum of gravitational potential energy (
) and translational kinetic energy (
), all measured in joules. In addition, gravitational potential energy is directly proportional to height (
) and translational kinetic energy is directly proportional to the square of velocity.
Besides, gravitational potential energy is increased at the expense of translational kinetric energy. Then, relative amounts at each position are described below:
Position A/Position E
,
Position B/Position D
, , for
Position C
,
Answer:
The only difference between a planet and a dwarf planet is the area surrounding each celestial body. A dwarf planet has not cleared the area around its orbit, while a planet has.
Explanation:
the three criteria of the IAU for a full-sized planet are: It is in orbit around the Sun. It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape). It has "cleared the neighborhood" around its orbit .
