Amover pushes a 30 kg crate across a level florr with a force of 250 n, but the crate accelerates at a rate of only 5.83 m/s squared because a friction force opposes the crate's motion. what is the magnitude of the force of friction?

What will a positive and a negative charge do if they are separated from each other?

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

Arunner is jogging at a steady 3.6 km/hr. when the runner is 2.9 km from the finish line, a bird begins flying from the runner to the finish line at 14.4 km/hr (4 times as fast as the runner). when the bird reaches the finish line, it turns around and flies back to the runner. even though the bird is a dodo, we will assume that it occupies only one point in space, i.e., a zero-length bird. how far does the bird travel? (b) after this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. the bird repeats the back and forth trips until the runner reaches the finish line. how far does the bird travel from the beginning? (i.e. include the distance traveled to the first encounter)