The maximum magnitude of the net force on the box is 20 N, which is only possible if the boy and the girl pull the box together in the same direction, horizontally and parallel to the ground.
The minimum magnitude of the net force on the box is 0 N, which will occur when the boy and the girl pull the box together in the parallel but opposite direction.
If either of them pulls at an angle from the horizontal, then the magnitude of the net force will be between 0 N and 20 N.
D. the motion of the source or observer
Answer: Radiation
Explanation:
There are three ways in which the thermal transfer occurs:
1. By Conduction, when the transmission is by the <u>direct contact</u>.
2. By Convection, heat transfer <u>in fluids </u>(like water or the air, for example).
3. By Radiation, by the <u>electromagnetic waves</u> (they can travel through any medium and in <u>vacumm</u>)
So, in the outter space is vacuum, this means the energy cannot be transmitted by convection, nor conduction. It must be transmitted by electromagnetic waves that are able to travel with or without a medium, and this is called radiation.
Answer:
Equation for SHM can be written
V = w A cos w t where w is the angular frequency and the velocity is a maximum at t = 0
V1 = w1 A cos w1 t
V2 = w2 A cos w2 t
V2 / V1 = w2 / w1 since cos X t = 1 if t = zero
V2 / V1 = 2 pi f2 / (2 pi f1) = f2 / f1 = T1 / T2
If the velocity is twice as large the period will be 1/2 long
