Which phrase best describes a gravitational force? A. a force that spins objects
B. a force that pulls objects toward each other
C. a force that can make objects both attract and repel each other
D. a force that eats only when two objects are in contact with each other

I'm pretty sure it should be B

Explanation:

When you think of gravity, it pulls objects towards the ground by force. So, gravitational force should be pulling objects towards each other. Please let me know if this isn't right! I hope that helps! ^^

the maxium height is 34m/s

you'd use the equation that establishes a relationship between  energy  and  wavelength, which looks like this

e=h⋅cλ, where

λ  - the wavelength of the photon; c  - the speed of light, usually given as  3⋅108m/s; h  -  planck's constant, equal to  6.626⋅10−34j s

plug the value you were given for the energy of the photon in the above equation to get the wavelength

e=h⋅cλ⇒λ=h⋅ce

λ=6.626⋅10−34js⋅3⋅108ms−1.257⋅10−24j=1.581⋅10−1m