Which of these reactions is responsible for energy radiating from stars, including the sun?
a)
nuclear fusion
nuclear fission
an exothermic chemical reaction
an endothermic chemical reaction
3

Acar of mass m goes around a banked curve of radius r with speed v. if the road is frictionless due to ice, the car can still negotiate the curve if the horizontal component of the normal force on the car from the road is equal in magnitude to 101) a) mv2/r b) mg/2. d) mg e) tan[v2/(eg)]

Calculate the ratio of h+ ions to oh– ions at a ph = 6. find the concentration of h+ ions to oh– ions listed in table b of your student guide. then divide the h+ concentration by the oh– concentration. record this calculated ratio in table a of your student guide. compare your approximated and calculated ratios of h+ ions to oh– ions at a ph = 6. are they the same? why or why not? record your explanation in table a. what is the concentration of h+ ions at a ph = 6? mol/l what is the concentration of oh– ions at a ph = 6? mol/l what is the ratio of h+ ions to oh– ions at a ph = 6? : 1

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?