1. A train increases its speed steadily from 10m/s to 20m/s in 1 minute. a) What is its average speed during this time, in m/s?
b) How far does it travel while increasing its speed?

It is either a  proton or a neutron im almost positive. hope this .

This ain't even a question. speak english

Gravity, from the center of mass of the box, extending downward normal force, from the floor under the box, extending upward, equal to gravity push force, acting at a point on the box, extending in the direction of motion friction, acting at any point on the box directly opposite the push, extending directly opposite to the motion

The correct option is this: the sound waves from the two trombones have slightly different frequencies.from the question given above, we are told that the loudness of the sounds were increasing and decreasing, this is because the frequencies of the two sounds are different. the means that the number of waves that pass a fixed point in a given amount of time differ for both sounds.