Why are birds considered keystone species in ecological succession?

Hydrogen atoms are excited by a laser to the =4n=4 state and then allowed to emit. what is the maximum number of distinct emission spectral lines (lines of different wavelengths) that can be observed from this system? 8 6 2 7 4 5 1 3 calculate the wavelength of the 4⟶14⟶1 transition. =λ=

Match these items. 1. coulombs __force 2. ohms __emf 3. centimeters __resistance 4. newtons __charge 5. volts __length

Part of a control linkage for an airplane consists of a rigid member cb and a flexible cable ab. if a force is applied to the end b of the member and causes it to rotate by θ = 0.5°, determine the normal strain in the cable. originally the cable is unstretched.