Answer:
If an object moves twice as fast its kinetic energy quadruples.
Explanation:
The kinetic energy (K₁) of a body of mass (m) that moves with speed (v) is:
K₁= 1/2 * m* v²
If we double the speed of the body, its kinetic energy (K₂) will be:
K₂= 1/2 * m*( 2v)²
K₂= 1/2 * m* 4 *v²
K₂= 4(1/2 * m *v²)
K₂= 4*K₁
Answer: C and D
Explanation: One of the first rule for total internal reflection to occur is that the ray must move from a dense to a less dense medium, hence refractive index of medium a must be greater than that of b.
When a ray moves from a dense to a less dense medium, the refracted ray moves away from the normal thus increasing the size of the angle of refraction (total internal refraction occurs when the angle of refraction is 90° and the angle of incidence at this point is known as the critical angle), hence the angle of incidence must be greater than the critical angle.
These points verifies option C and D
The two factors that affect the period of a pendulum are the length of the string and the distance in which the pendulum falls.
Hope this helps! I would greatly appreciate a brainliest! :)
<span>So we want to know what statement is an accurate description of vibrations. So humans can hear sound frequencies from 20-20000 Hz. Below 20 Hz is infra sound and above 20000 Hz is ultra sound. Humans cant hear both infra sound and ultra sound so the correct answer is A.</span>
