A boy ties a stone to the end of a string which he then whirles above his head round a circular path of radius 15cm . If the stone makes 20 oscillation in 10 seconds, calculate the angular and linear speeds of the stone.

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron

Identify the correct relation showing that the radius r of the orbit of a moon of a given planet can be determined from the radius r of the planet, the acceleration of gravity at the surface of the planet, and the time τ required by the moon to complete one full revolution about the planet. determine the acceleration of gravity at the surface of the planet jupiter knowing that r = 71 492 km and that t= 3.551 days and r= 670.9 × 10^3 km for its moon europa.

The amount of potential energy possessed by an elevated object is equal to what?