The only real difference is that common seismic waves travel through the ground and sound waves travel through the air. If you had a pipe attached to granite and you were listening to it, you might detect both.
Sound travels better in water
Answer: 3 m.
Explanation:
Neglecting the mass of the seesaw, in order the seesaw to be balanced, the sum of the torques created by gravity acting on both children must be 0.
As we are asked to locate Jack at some distance from the fulcrum, we can take torques regarding the fulcrum, which is located at just in the middle of the length of the seesaw.
If we choose the counterclockwise direction as positive, we can write the torque equation as follows (assuming that Jill sits at the left end of the seesaw):
mJill* 5m -mJack* d = 0
60 kg*5 m -100 kg* d =0
Solving for d:
d = 3 m.
Answer:
D. Upward force on the shuttle
Explanation:
The hot gas from space shuttles released downward causes an upward force on the shuttle and propels it up the more.
- This hot gas is produced from super cooled oxygen and hydrogen tanks within the shuttle.
- The upward force on the shuttle allows the craft to escape the gravitational pull of the earth on the shuttle
- Special level of rapid acceleration must be attained for the shuttle to escape the earth pull.
