The earth's atmosphere is divided into five layers. in which layer does all life exist? a) exosphere b) mesosphere c) stratosphere d) troposphere

Abucket full of water weights 4 kg and water well is 10m deep. a girl draws water from the well. it takes the girl 3 minutes to draw a bucket full of water from the well. what is the power of the girl?

If the work required to stretch a spring 3 ft beyond its natural length is 15 ft-lb, how much work is needed to stretch it 27 in. beyond its natural length?

The space between two 15-in.-long concentric cylinders is filled with glycerin (viscosity = 8.5 × 10-3 lb·s/ft2). the inner cylinder has a radius of 1 in. and the gap width between cylinders is 0.1 in. determine (a) the torque and (b) the power required to rotate the inner cylinder at 180 rev/min. the outer cylinder is fixed. assume the velocity distribution in the gap to be linear.