Asquare is cut out of a copper sheet. two straight scratches on the surface of the square intersect forming an angle theta. the square is heated uniformly. as a result, the angle between the scratches? a) increasesb) decreasesc) stays the samed) depends on whether theta is obtuse or acute

What is the average speed of a car that travels 40mph for 1 hour and 60 mph in another hour will mark brainliest

1kg of water needs to recieve 4200j of energy to go from 90 degrees to 91 degrees. what is the specific heat capacity of water? what are the units?

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".