When to Expect Morning Sickness. For most women, morning sickness starts about the sixth week of pregnancy, which is about three weeks after conception, assuming you have a normal menstrual cycle. It can start as early as the fourth week, which is right around when you might get your period.hen to Expect Morning Sickness. For most women, morning sickness starts about the sixth week of pregnancy, which is about three weeks after conception, assuming you have a normal menstrual cycle. It can start as early as the fourth week, which is right around when you might get your period.
Electromagnetic waves travel in a vacuum whereas mechanical waves do not. The mechanical waves need a medium like water, air, or anything for it to travel. The ripples made in a pool of water after a stone is thrown in the middle are an example of mechanical waves.hile an electromagnetic wave is called just a disturbance, a mechanical wave is considered a periodic disturbance. Mechanical waves are also called elastic waves as their propagation depends on the elastic properties of the medium through which the waves pass.
c. Electromagnetic waves can travel through empty space; mechanical waves can't d. Electromagnetic waves are long chains of vibrating molecules; mechanical waves aren't 7. Which of the following are electromagnetic waves? a. Water waves b. Radio waves c. Sound waves d. Seismic waves 8. What type of waves carry energy at a right angle to the direction of the energy flow? a. Compression waves b. Transverse waves c. Sound waves d. P-waves 9. How is wavelength measured? a. b. c. d. 10. What can you infer about a wave with a short wavelength? a. It has a low amplitude b.