In lightning , light is seen first and sound is heard later it is due to 1)optical illusion
2) variation in temperature
3) position of observer
4) difference of velocities of light and sound

Write short note on the following ; collision theory, rotation angle and angular velocity, centripetal acceleration, coriolis force, and newton's law of gravitation.

Janelle made a hypothesis bout the uneven temperatures inside her house during winter. she believes that 50% of the ducts are blocked and she plans to investigate. if she wants to prove her hypothesis using scientific processes what should she do next?

Which terms describe the purpose of antennas on devices that use radio waves? transmit and receivemodify and amplifyamplify and receivemodify and transmit