A series of pulses of amplitude 0.1 m are sent down a string that is attached to a post at one end. The pulses are reflected at the post and travel back along the string without loss of amplitude. What is the amplitude at a point on the string where two pulses cross if the string is rigidly attached to the post? Answer in units of m.

(a) if the string is rigidly attached to the post it means that the reflected wave is upside down from the original. Thus they add to zero when they cross.

(b) if the string is freely attached to the post it means the reflected wave is rightside up. Thus when they cross the amplitudes add so 0.10 + 0.10 = 0.2 m.

Explanation:

the force on the thing and the distance the force moves the thing

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it