A sample of an ideal gas is in a tank of constant volume. The sample absorbs heat energy so that its temperature changes from 387 K to 774 K. If v1 is the average speed of the gas molecules before the absorption of heat and v2 their average speed after the absorption of heat, what is the ratio v2 v1 ? 1. v2 v1 = √ 2 2. v2 v1 = 2 3. v2 v1 = 1 2 4. v2 v1 = 4 5. v2 v1 = 1

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 710 n/m. it is initially at rest on an inclined plane that is at an angle of θ = 23° with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is μk = 0.19. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. a) what is the block's initial mechanical energy? b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

Ain is , is 's of ? 0.62 0.79 1.27 1.50

Which planets are visible without a telescope