If a wave has a wavelength of 2m and a frequency of 500 hz, what is its speed

To do work, this truck uses energy stored in chemical fuel and an electrical battery. how much total energy does this truck put out?

If gases like carbon dioxide and methane make up less than 1% of the total atmosphere, why is it important for scientists to monitor changes in percentages of these gases?

Ahanging spring stretches by 35.0 cm when an object of mass 450 g is hung on it at rest. in this situation, we define its position as x = 0. the object is pulled down an additional 18.0 cm and released from rest to oscillate without friction. what is its position x at a moment 84.4 s later? express your answer in cm.