A mass on a spring vibrates in simple harmonic motion at a frequency of 8.0 Hz and an amplitude of 2.0 cm. If a timer is started when its displacement is a maximum (hence x = 2.0 cm when t = 0), what is the speed of the mass when t = 3.0 s?
Select one:
a. 50 m/s
b. zero
c. 2.0 m/s
d. 100 m/s
e. 3.0 m/s

What pressure difference is required between the ends of a 2.0-m-long, 1.0-mm-diameter horizontal tube for 40 c water to flow through it at an average speed of 4.0 m/s?

Which of the following can enter and exit a closed system? a. matter and energy b. neither energy nor matter c. matter but not energy d. enrgy but not matter

Asquare isothermal chip is of width w=5 mm on a side and is mounted in a substrate such that its side and back surfaces are well insulated; the front surface is exposed to the flow of a coolant at tinf=15 °c. from reliability considerations, the chip temperature must not exceed t=85 °c. if the coolant is air and the corresponding convection coefficient is h=200 w/m2 x k, what is the maximum allowable "power" of the chip? if the coolant is a liquid for which h=3000 w/m2 x k, what is the maximum allowable power of the chip?