Un bloque de hielo con masa de 4.00 kg está ini-
cialmente en reposo sobre una superficie horizontal sin fricción. Un

obrero le aplica entonces una fuerza horizontal F y el bloque se mueve sobre el eje x, de modo que su posición en función del tiempo está dada por x(t) = at + bt , donde a = 0.200 ms , b = 0.0200 ms . a) Calcule la velocidad del objeto en t = 4.00 s. b) Calcule la magnitud
de F en t = 4.00 s. c) Calcule el trabajo efectuado por la fuerza F durante los primeros 4.00 s del movimiento.

What defines the mass number of an isotope? a. the sum of the neutrons and protons b. the sum of the neutrons and electrons c. the number of neutrons d. the number of protons

The key to stability is feedback between the reservoir and the fluxes into and/or out of the reservoir. assume that the rate of outflow from a reservoir depends on the size of the reservoir according to the following relationship: outflow rate= k x (size of reservoir), where k is a constant. a reservoir of water has a volume of 5000 liters, and the rate of outflow at steady state is 25 liters per minute. what is k? (give both the numerical value and its units.) what is the residence time? what is the relationship between k and the residence time?

Two students, each riding bicycles, start from the same apartment building and ride to the same building on campus, but each takes a different route. the first student rides 1100 m due east and then turns due north and travels another 1430 m before arriving at the destination. the second student heads due north for 1930 m and then turns and heads directly toward the destination.at the turning point, how far is the second student from the destination?