If a dog chases its tail in a perfect circle of radius r at constant speed v, which of the following is true?

Question

A. The dog's acceleration is zero.
B. The dog's velocity is constant.
C. The sum of the forces, F , acting on the dog is zero.
D. The time it takes the dog to make one circle is given by t = 2 r/v.

You attempt to push a heavy box of mass M sitting at rest on a level floor, but are unable to move it with a force F . If the coefficients of static and kinetic friction between the box and the floor are s and k respectively, and s > k, what can we definitely say about the force F ? (g = gravitational acceleration)

A. F < M g
B. F < kM g
C. F < sM g
D. 2F > sM g

Answer 1

Right answer choices for B-D
B. F < µkMg
C. F < µsMg
D. 2F > µsMg