I need help guys! please! Question:
A girl sits on a tire swing and is pushed in a circular motion by her father. Her tangential speed is 2.8 m/s and the girl travels in a circle with a diameter of 4.0 m. What is the girl's centripetal acceleration?

1.4 m/s 2
0.7 m/s 2
3.9 m/s 2
4.0 m/s 2

Figure 9 on page 362 shows various motions of balls. the curved path followed by the yellow ball in b in picture b is result of a) inertia b) centripetal motion c) gravity and horizontal velocity d) linear motion

How to tell if two objects are in thermal equilibrium 1.the objects have the same temperature 2.the objects are the same size 3.the objects are touching each other 4.the objects temperatures are changing

Two identical stars with mass m orbit around their center of mass. each orbit is circular and has radius r, so that the two stars are always on opposite sides of the circle. (a) find the gravitational force of one star on the other. (b) find the orbital speed of each star and the period of the orbit. (c) how much energy would be required to separate the two stars to infinity?