Answer:
A: Sound waves produce an echo
Explanation:
because the cup is a hard smooth surface you can hear the voice
Answer:
1.1 Two poles: North and South Poles.
1.2 - Staple pin - Nail - Tip of my phone charger - Metal keys - Cloth Hanger
1.3 - Wooden bed cot - Plastic pen - Game pad - Wooden shelf - Paper - A T-shirt
1.4 Yes
1.5 No
This is an example of conduction
The boundary between the crust and mantle is marked by a seismic-velocity discontinuity is called Mohorovicic discontinuity.
Mohorovicic discontinuity was discovered by Andrija Mohorovicic in 1909 who was a Croatian seismologist. He realized that the velocity of a seismic wave is related to the material's density where it is moving through. He decoded that the acceleration of the seismic waves that are observed within outer shell of the earth is a compositional change. Thus, the acceleration should be caused by a material of higher density.