Amover pushes a 255 kg piano
with a 77.5 n force to the left, while
a second mover pulls the piano
48.7 n to the left. what is the
acceleration of the piano?
(watch your minus signs.)
(unit = m/s)

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.

Which body part transports oxygen removes waste materials in carries nutrients to the body as part of the circulatory system