Physics Answers

A car travels at 20 m s-1 for 1 h, and then accelerates at 3 m s-2 for 60 s. What is the distance traveled?

What is entropy

If a beam of electrons of energy 0.04eV impinges on any energy barrier of height 0.03eV and of infinite width then the fraction of electrons reflected is 0.2, 0.1, 0, 0.9

A 145 gram sample of a certain radioactive isotopes had a half-life of 500 years. If 4 half-lives go by, how much of the original isotope is left?

Two particles with electric charges Q and —3Q are separated by a distance of 1.2 m. (a) If Q = 4.5 C, what is the electric force between the two particles? (b) If Q —4.5 C, how does the answer change?

Consider two vectors A and B. Vector A has a magnitude of 13 and points at an angle of 72 degrees above the +x axis. Vector B has a magnitude of 8 and points at an angle of 31 degrees below the +x axis.

a.     What are the x and y components of vector A?

b.     What are the x and y components of vector B?

c.     Suppose vector C is defined as C=A+B. What are the x and y components of vector C?

d.     What is the magnitude of vector C?

e.     At what angle does vector C point?

A ball is thrown straight upward from the surface of earth which statement best describes the balls velocity and acceleration at the top of its flight

what does the area of velocity-time graph give?

a stone is thrown directly upward with initial speed V0, returning after a certain time to its launch point. When it reaches its maximum height we can say that:
A. displacement is zero
B. Acceleration is zero
C. the position is zero
D. speed is zero
E. time is zero

a deer goes from point a to point b in 7.00 seconds with constant acceleration, traveling 70.0m. Its speed passing through point B is 15.0m / s. The speed at point A was:

A. 35,0 m/s

B. 230 m/s

C. 5,00 m/s

D. 4,29 m/s

E. 260 m/s