Los clavadistas de la “quebrada de Acapulco” se lanzan horizontalmente desde una plataforma rocosa, que está aproximadamente a 35 m sobre el
agua; sin embargo, ellos deben librar protuberancias rocosas al nivel del mar,
que se extienden hasta 5 m desde la base del acantilado directamente debajo
su punto de lanzamiento.
a) ¿Cuánto tiempo permanecen en el aire?
b) ¿Qué rapidez mínima inicial es necesaria para lograrlo?

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".

Along wire carrying a 4.2 a current perpendicular to the xy-plane intersects the x-axis at x=−1.7cm. a second, parallel wire carrying a 3.0 a current intersects the x-axis at x=+1.7cm. part a at what point on the x-axis is the magnetic field zero if the two currents are in the same direction? express your answer to two significant figures and include the appropriate units.

Two technicians are discussing a starter that clicks repeatedly when the key is turned to the crank position. technician a says the solenoid hold-in winding is open. technician b says the solenoid pull-in winding is open. who is correct?