Avisitor to a lighthouse wishes to determine the height of the tower. the visitor ties a spool of thread to a small rock to make a simple pendulum, then hangs the pendulum down a spiral staircase in the center of the tower. the period of oscillation is 9.01 s. what is the height of the tower? the accel- eration due to gravity is 9.81 m/s2 . answer in units of m.

We have a colorless transparent liquid. it looks like water. we seperated it into a solid and a liquid by evaporration and condention was this a chemichal or a physical seperation a. chemical seperation b. physical seperation

Acar drives toward the right over the top of a hill, as shown below. which arrow represents the centripetal acceleration? w x y z

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants