Two rowers, who can row at the same speed in still water, head across a river.

the first rower (alice) heads straight across (but of course her boat is pulled downstream by the current).

the second rower (bianca) heads slightly upstream, so that with the pull of the current she arrives directly opposite their starting point.

who arrives at the other side first?

a) alice
b) bianca
c) it's impossible to tell without more information.

There is a theory that indicates that dinosaurs became extinct when about 65 million years ago, a large asteroid hit the earth surface. dust caused by this collision blocked the sunlight reaching the earth's surface and many forms of life became extinct due to the cold. fearing this threat, how large the radius of an asteroid should you be looking for if the dangerous asteroid size is approximately the same as the one that killed the dinosaurs? available data suggests that about 18% of that asteroid's mass ended up as a dust spread evenly over earth after eventually settling out of the upper atmosphere. about 0.0180 g/cm^2 of dust, which is chemically different than the earth's rock, covered the earth's surface. typical asteroids have a density of about 1.9 g/cm^3. now that we know the size of the asteroid, how much energy was released during impact, assuming all of it was just the kinetic energy of the asteroid right before the impact?

In a given chemical reaction, the energy of the products is greater than the energy of the reactants. which statement is true for this reaction?

Which statement correctly describes a step-up transformer? a. it increases the amount of electric energy available. b. it increases the voltage of an electric current. c. it changes direct current into alternating current. d. it has more loops of wire in its primary coil.