Astar is transited by a planet. from the measured period t and the transit duration tdur alone, show that one can obtain an upper bound on the density of the transited star: p.,max 3r/(gr2) hint: combine kepler's law and eq. 6.7 to eliminate the separation a, and then extract the density of the spherical star. the upper bound is obtained by assuming an impact parameter b 0. a. b. suppose that from the transit light curve one can measure the total transit duration, tt, between the "first contact" and the "last contact" of the planet and the star, and also the duration of the "flat" part of the transit, t, during which the planet is fully superimposed on the star's disk. show that in this case, utilizing also the transit depth (eq. 6.6), b can be determined, and hence the star's density (and not just upper bound) can be found.

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.

distance = 150m

displ = root (50 ^2 + 100^2)

root(2500+10000)

root 125000