Why might skin not be able to produce enough vitamin d

Which experimental observation led scientists to speculate that cathode rays contained particles that were constituents of all matter? the rays were deflected by electrical fields. the rays were deflected by magnetic fields.

What is the area of a rectangle that has width of 1.50 x 103 cm and a length of 2.30 x 106 cm? Keep all the significant figures.

How many neutrons does element X have if its atomic number is 59 and its mass number is 164?

Write the equation for speed

In a ballistics test, a 26 g bullet traveling horizontally at 1000 m/s goes through a 35-cm-thick 400 kg stationary target and emerges with a speed of 950 m/s. The target is free to slide on a smooth horizontal surface.

A young man walks daily through a gridded city section to visit his girlfriend, who lives m blocks East and nblocks North of where the young man resides.

Aliens from planet Moby have three alleles for skin color: R (red) W (white) and B (Blue). If all of these alleles are codominant and aliens on planet moby can only inherit two alleles for a gene, what are the six possible genotypes for skin color

The difference between two numbers is 15. When twice the smaller number is subtracted from three times the larger number, the difference is 58. What is the larger number?

Vector A makes equal angles with x, y and z axis. value of its components (in terms of magnitude of vector A will be?

What has become an important alternative to Piagetian approaches?