A person of mass m stands on roller skates facing a wall. After pushing against the wall with a constant force F he moves away, reaching speed v after a distance d. What is the work done by F?

What is speed in a particular direction is called?

When AC is changed into DC to charge a laptop or phone, is the resulting voltage perfectly constant? A. Yes B. No, but it can be made pretty close C. No, in fact sometime it's negative

Which of the following groups of elements are included in the main group of elements?

A car moves with an initial velocity of 19 m/s due north. (Part A) Find the velocity of the car after 5.6 s if its acceleration is 1.6 m/s^2 due north. (Part B) Find the velocity of the car after 5.6 s if its acceleration is 1.5 m/s2 due south.

What keeps a star inflated against the pull of gravity, which wants the whole thing to collapse on the core?

Which of the following best describes the earth's average surface temperature for the past 900,000 years? A. a steady warming trend B. fairly steady temperatures until recently C. prolonged periods of cooling and warming D.

A capacitor with initial charge q0 is discharged through a resistor. What multiple of the time constant τ gives the time the capacitor takes to lose (a) the first 1/8-th of its charge (b) 7/8-th of its charge?

A sheet of paper has a mass of 5 grams. The paper is dropped from a high building twice (it reaches terminal speed in both cases), once as a flat paper of area 600 cm2 and once crumpled as a ball of radius 2 cm.

When the particle with charge q reaches the center of the original square, it is, as stated in the problem, momentarily at rest. Is the particle at equilibrium at that moment?

How does the bohr model represent electrons around the central nucleus why think of the spectra?