You are standing outside with two speakers. The temperature is 0 degrees C. The two speakers are playing sound of the same frequency: a pure sinusoidal sound of the same frequency at the same phase. The speakers are playing at different amplitudes. One speaker is 1.230 meters from you and one is 1.425 meters from you. You hear no sound. Which of the following is a possible frequency of the sound being played? a. 993 Hz
b. 331 Hz
c. 4965 Hz
d. 1655 Hz
e. 662 Hz

What do you think car designers do if the damage caused by a crash test is too severe?

Aperson gives a shopping cart an initial push along a horizontal floor to get it moving, and then lets go. the cart travels forward along the floor, gradually slowing as it moves. consider the horizontal force(s) on the cart while it is moving forward and slowing. which of the following statements is correct? (a) both a forward and a backward force are acting on the cart, but the forward force is larger. (b) only a forward force is acting which diminishes with time. (c) both a forward and a backward force are acting on the cart, but the backward force is larger. (d) only a backward force is acting, no forward force.

Consider a hydrogen atom in the ground state. what is the energy of its electron? =e= jj now consider an excited‑state hydrogen atom. what is the energy of the electron in the =5n=5 level? =e5= j