Your teacher walks outside the classroom to have a conversation with the principal. unknown to the teacher, while she is outside the room, the sound waves are transmitted around the edge of the door and spread out on the other side and you can hear the conversation. this is due to sound wave
a) absorption.
b) diffraction.
c) interference.
d) reflection

Two particles of masses m and 2m are placed on a smooth horizontal table. a string, which joins these two masses, hangs over the edge supporting a pulley, which suspends a particle of mass 3m.the pulley has negligible mass. the two parts of the string on the table are parallel and perpendicular to the edge of the table. the hanging parts of the string are vertical. find the acceleration of the particle of mass 3m.

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

Suppose a comet has an orbital period of 309.1 years around the sun. what is it’s average distance from the sun?