Apaper weight is dropped from the roof of a block of multi storey flats. each storey being 3 metre high. it passes the ceiling of the 20th storey at 30m/s. if g=10m/s2,how many storeys does the flat have?

Which of the following elements is in the same period as phosphorus? a. carbon c. nitrogen b. magnesium d. oxygen select the best answer from the choices provided a b c d

The air that we breath is made mostly of which gaseous molecule

Two charged particles, q1 and q2, are located on the x-axis, with q1 at the origin and q2 initially at x1 = 12.2 mm. in this configuration, q1 exerts a repulsive force of 2.62 µn on q2. particle q2 is then moved to x2 = 18.0 mm. what is the force (magnitude and direction) that q2 exerts on q1 at this new location? (give the magnitude in µn.)