physics UAE- Gravitation

the paths of the planets are ellipses, with the Sun at one focus.

• Kepler’s 1st law

• Kepler’s 2nd law

• Kepler’s 3rd law

• Newton Law of Gravity

an imaginary line from the Sun to a planet sweeps out equal areas in equal time intervals

• Kepler’s first law

• Kepler’s 2nd law

• Kepler’s 3rd law

• Newton law

The square of the ratio of the period of planet A to the period of planet B is equal to the cube of the ratio of the distance between the centers of planet A and the Sun to the distance between the centers of planet B and the Sun

• Kepler’s first law

• Kepler’s 2nd law

• Kepler’s 3rdlaw

• Newton law

Kepler’s third law

• $\left(\frac{Ta}{Tb}\right)^2=\left(\frac{r_a}{r_b}\right)^3$

• $\left(\frac{Ta}{Tb}\right)^3=\left(\frac{ra}{rb}\right)^2$

• $\left(\frac{r_a}{Tb}\right)^2=\left(\frac{Ta}{r_b}\right)^3$

solve the problem: ( in 3 min)

the orbital radii of Jupiter’s moons using the diameter of Jupiter as a unit of measure. He found that Io, the closest moon to Jupiter, has a period of 1.8 days and is 4.2 units from the center of Jupiter. Callisto, the fourth moon from Jupiter, has a period of 16.7 days. Using the same units that Galileo used, predict Callisto’s distance from Jupiter?

Tc =16.7 days Ti =1.8 days rc =4.2 units ri =?

• 19 units

• 190 units

• 90 units

• 1900 units

Satellite; A geosynchronous satellite is one that appears to remain over one spot on Earth, as shown in Figure . Assume that a geosynchronous satellite has an orbital radius of 4.23"10⁷ m. Calculate its speed in orbit.

Earth radius =(6.38x10⁶ m) , Earth mass=(5.97x10²⁴ kg)

• 3.07x10³ m/s

• 9424900 m/s

• 0.47 m/s

• 0.22 m/s

Satellite; A geosynchronous satellite is one that appears to remain over one spot on Earth, as shown in Figure . Assume that a geosynchronous satellite has an orbital radius of 4.23"10⁷ m. Calculate its period in orbit.

Earth radius =(6.38x10⁶ m) , Earth mass=(5.97x10²⁴ kg)

• 1.2x10⁹ s

• 8.66 x10³ s

• 8.66x10⁴ s

• 1.2x10⁴ s

A 1.25-kg book in space has a weight of 8.35 N. What is the value of the gravitational field at that location?

• 6.68 N/kg

• 0.149 n/kg

• 9.81 m/s²

• 5.9 m/s²

what is the earth period in seconds?

• 86400 s

• 1440 s

• 604800 s

• 24000 s

Two 1.00-kg masses have their centers 1.00 m apart. What is the force of attraction between them?

G=6.67x10¹¹ N.m²/kg²

• 6.67x10¹¹ N

• 26.68x10¹¹ N

• 13.34 x 10¹¹ N

• 19.6 N