Atrain travels 77 kilometers in 4 hours, and then 76 kilometers in 2 hours. what is its average speed?

Density of salty water as compared to the density of pure water is(a) is less(b) is always equal(c) is always more(d) may be less or more

Orque can be calculated by multiplying the force (n) applied at 90? to the lever arm at a distance (m) from the pivot point (point of rotation), the compound si unit for the torque is n? m. if the force (at 90? to the lever arm) applied is 15 n and it is applied at 2.0 m from the pivot point (point of rotation), what is the torque on the lever?

Astone is thrown into a pond. what happens to the amplitude of the resulting waves as they get farther from the point where the stone hit the water? explain.