When conducting an experiment, which of the following is generally true?

a. it is unsafe to preform a large number of experimental trials.
b. the number of trials preformed does not affect the validity of the results.
c. performing a smaller number of experimental trials makes the results more dependable.
d. performing a larger number of experimental trials makes the results more dependable.

Atelevision set that has been running for a while heats up even the air around it. which two laws of thermodynamics could be used to analyze this scenario

Explain why electric current cannot exist if a current doesn't have a voltage source.

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".