During pregnancy, an umbilical cord and a placenta join the embryo to the mother. At birth the umbilical cord is cut.
Stem cells can be obtained from the umbilical cord.
Many people think that the stem cells for treating human conditions should be obtained
from umbilical cords rather than human embryos.
Suggest one reason why

An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Water in a partially filled large tank is to be supplied to the roof top, which is 8 m above the water level in the tank, through a 2.2-cm-internal-diameter pipe by maintaining a constant air pressure of 300 kpa (gage) in the tank. if the head loss in the piping is 2 m of water, determine the discharge rate of the supply of water to the roof top in liters per second.