The focal length of the eye-lens system will be exactly 2.0 cm. The lens thickness is altered depending on the distance of the object being viewed so that the focal length is ALWAYS equal to the lens-retina distance. If this is not true fr an individual, they need glasses :)
Any change in the magnitude or direction of velocity is "acceleration".
Jack------------ force of 92.5 n eastward-------Fjack(X)=92.5 n Fjack(Y)=0
<span>jill ------------------------------- force of 89.9 n northeast
Fjill(X)=cos45*89.9=63.57 n
</span>Fjill(Y)=sin45*89.9=63.57 n<span>
</span>jane -----------------------------force of 163 n southeast
Fjane(X)=cos45*163=115.26 n
Fjane(X)=-sin45*163=-115.26 n
Ftotal (X)=92.5+63.57+115.26=271.33 n
Ftotal (Y)=0+63.57-115.26=-51.69 n
Fotal=((271.33)^2+(-115.26)^2) ^0.5=294.80 n southeast
the magnitude of the net force the people exert on the donkey. is 294.80 n southeast
Protons are usually regarded by their mass, as mass is not specific to any gravitational acceleration. However, if you wished to find the weight of a proton on Earth, it would be:
Force (weight) = mass of proton * acceleration due to Earth's gravity
F = ma
F = (1.62 x 10^-27)(-9.8)
F = 1.5876 * 10^-26N