HELP NO PLEASE Which of the following materials is most efficient at transferring vibrations?
a) water
b) air
c) pillow
d) steel rod

The motor m applies a time-varying force of f (200 t) n, where t is in seconds. box b with mass 200 kg starts from rest, and the coefficients of kinetic and static friction are 0.2 and us 0.3 the acceleration due to gravity is g 9.8 m/s2 b 300 a) find the time ' when the box starts to move. b) calculate the speed of the crate at 3 s c) calculate the power delivered by the motor at t 3 s

Anybody wanna ? (picture included? )

Select the three ways that the parallel-plate capacitor differs from a car battery.