Suppose that two boys pull a sled with forces of 2.0 x 104 N at a 15° angle to the left of the center of the sled, and 1.8 x 104 N at an angle of 25° to the right of the center of the sled, respectively.

If the sled does not move, what is the other force that must be acting on the sled?

a. 2.1 x 104 N at 260°
b. 2.1 x 104 N at 290°
c. 3.6 x 104 N at 266°
d. 3.6 x 104 N at 282°

from 1609, galileo galilei used the recently invented telescope to observe the sun, moon and planets. he saw the mountains and craters of the moon, and for the first time revealed the planets to be worlds in their own right. galileo also provided strong observational evidence that planets orbited the sun.

his discoveries about the moon, jupiter's moons, venus, and sunspots supported the idea that the sun - not the earth - was the center of the universe, as was commonly believed at the time.galileo turned his gaze toward venus, the brightest celestial object in the sky - other than the sun and the moon.

i believe the answer is a

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