He arrhenius equation shows the relationship between the rate constant k and the temperature t in kelvins and is typically written as k=ae−ea/rt where r is the gas constant (8.314 j/mol⋅k), a is a constant called the frequency factor, and ea is the activation energy for the reaction. however, a more practical form of this equation is lnk2k1=ear(1t1−1t2) which is mathematically equivalent to lnk1k2=ear(1t2−1t1) where k1 and k2 are the rate constants for a single reaction at two different absolute temperatures (t1 and t2). part a the activation energy of a certain reaction is 39.4 kj/mol . at 28 ∘c , the rate constant is 0.0140s−1 . at what temperature in degrees celsius would this reaction go twice as fast

A23 kg log of wood begins from rest, 300 m up a sluice (a water track used to transport logs, think of it as an inclined plane with negligible friction) inclined at 20° to the horizontal. after it reaches the flat waterway at the bottom it collides elastically with a 100 kg block of wood initially at rest near the base of the incline. (a) how long does it take the 23 kg log to travel down the incline? (b) what is the speed of the 23 kg log at the bottom of the incline? (c) what are the velocities of both blocks of wood after the collision? (d) what is the total kinetic energy before the collision? (e) what is the kinetic energy of the 23 kg log after the collision? (f) what is the kinetic energy of the 100 kg block of wood after the collision? (g) what is the total kinetic energy after the collision? (h) compare the total initial and total final kinetic energies. is this consistent with what you would expect for elastic collisions? explain!

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative

Suppose a diode consists of a cylindrical cathode with a radius of 6.200×10^−2 cm , mounted coaxially within a cylindrical anode with a radius of 0.5580 cm . the potential difference between the anode and cathode is 260 v . an electron leaves the surface of the cathode with zero initial speed (v initial=0). find its speed vfinal when it strikes the anode.