When is something weightless

From left, a lens labeled 1 flat on the left and convex on the right, a thick lens labeled 2 double convex, a lens labeled 3 convex on the right and slightly concave on the left, a lens labeled 4 flat on the left and concave on the right, a lens

A train rolls past a stationary observer. To him, the train is moving at a speed of 23 m/s west, and a woman on the train is moving at a speed of 22.4 m/s west. How long does it take the woman to move 13 m relative to the train?

Which has more volume feathers or rocks

Suppose that with a pulley system, you need to exert a force of 1,400 N to lift a heavy object. But without the pulley system, you need to exert 4,200 N to lift the object. What is the mechanical advantage of the pulley system

Which system protects us from radiation and the vacuum of space? a. geosphere b. hydrosphere c. atmosphere d. biosphere

What is the total number of atoms in the following formula? CaBr2 4 3 2 1

Object A with a mass of 500 kilograms hits stationary object B with a mass of 920 kilograms. If the collision is elastic, what happens after the collision? A) Both object A and object B move forward but with different velocities.

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?