A boy standing on a stationary lift (open from above) throws a ball upwards with the maximum initial speed he can, equal to 49 m s -1 . How much time does the ball take to return to his hands? If the lift starts moving up with a uniform speed of 5 m s -1 and the boy again throws the ball up with the maximum speed he can, how long does the ball take to return to his hands?

Asatellite that goes around the earth once every 24 hours iscalled a geosynchronous satellite. if a geosynchronoussatellite is in an equatorial orbit, its position appearsstationary with respect to a ground station, and it is known as ageostationary satellite find the radius rof the orbit of a geosynchronous satellite that circles the earth.(note that ris measured from the center of the earth, not the surface.) you mayuse the following constants: the universal gravitational constant g is 6.67 \times 10^{-11}\; {\rm n \; m^2 / kg^2}. the mass of the earth is 5.98 \times 10^{24}\; {\rm kg}. the radius of the earth is 6.38 \times 10^{6}\; {\rm m}.