A. A 0.60 kg bullfrog is sitting at rest on a level log. How large is the normal force of the log on the frog? b. A second 0.60 kg bullfrog is on a log tilted 0.30° above horizontal. How large is the normal force of the log on this frog?

a. 5.88 N

b. 5.09 N

Explanation:

Check attachment for drawings of the free-body diagrams.

(a) As we can see on our free-body diagram, the weight force and the normal force are the only forces acting on the y-direction.

Since the bullfrog is in a state of equilibrium, due to it being at rest, we can say that the weight force and normal force are equal to each other.

The weight force w is equal to mg, so we can plug the weight of the frog (0.60 kg) and the force of gravity (9.8 m/s²) to find the weight force.

The normal force and the weight force are equal to each other; therefore, the normal force is also equal to 5.88 N.

(b) As seen on the free-body diagram, the two forces that are in the y-direction are the normal force and the y-component of the weight force.

Therefore, by finding the force of the y-component of the weight force, we can find the normal force since they are equal to each other because the bullfrog is not moving up or down.

We know that the weight force is equal to 5.88 N, so we can plug this value into the y-component for the weight force:

Since the y-component of the weight force and the normal force are equal to each other, the normal force is also equal to 5.09 N.