Sketch both, the time domain AM signal and its frequency spectrum and explain what you see in terms of themodulation property of the Fourier transform.(Hint: How is the frequency spectrum of the message signal(co-sinusoid of 880 Hz) plus a DC component in base band, i. e. before modulation?)

see the attachment

Explanation:

In frequency spectrum there is no change in value of frequency of signal. However, The amplitude of signal after modulation increases. The fourier transform of sinwct is

1/2(F(w+wc) - F(w-wc))

For 2sinwct, the fourier transform is,

(F(w+wc) - F(w-wc))

In frequency domain, in AM only amplitude changes. Frequency remains same

this is a good question! i'll do some research and come back when i have the answer!

one person pulls 90n one way and the other has 100n pulling the other way.

so the net force = 90 - 100 = -10n,

or the ans can be 10n if the picture shows -90n and 100n instead.