Explanation:
Definition of electromagnetic wave. : one of the waves that are propagated by simultaneous periodic variations of electric and magnetic field intensity and that include radio waves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
Answer: primary ecological succession
Explanation:
Primary ecological succession: This occurs when a certain or some organisms dominate an area that was uninhabited of life. This may happen after a natural disaster that leaves the land barren. The presence of these organisms on the barren land will help the soil occupied to gain nutrients which will eventually allow some other plants to grow on it. The growth of plants will later invite insects and insects may invite animals.
To solve this problem we will apply the concept of rotational kinetic energy. Once this energy is found we will proceed to find the time from the definition of the power, which indicates the change of energy over time. Let's start with the kinetic energy of the rotating flywheel is

Here
I = moment of inertia
Angular velocity
Here we have that,


Replacing the value of the moment of inertia for this object we have,



The expression for average power is




Therefore the correct answer is 620s.
Answer:150N
Explanation:
Total mass=mass of skate board + mass of rider
Total mass(m)=46kg + 4kg
Total mass(m)=50kg
Acceleration(a)=3m/s^2
Force(f)=mass x acceleration
Force=50 x 3
Force=150N
This is a conservation of momentum question. Initial momentum of the system is the momentum of ball 1 plus the momentum of ball 2. The final momentum of the system should be 0 since the balls stand still after the collision.
mv + mv = 0
mv = -mv
(20)(20) = -(40)Vi
400 = -40Vi
Vi = -10
So ball 2 should travel at 10m/s to the left