4) jessica and martin start riding their bicycles towards each other at 2 pm. at 2 pm, they are 25 miles apart. jessica rides her bike at a constant rate of 15 miles per hour and martin rides his at a constant rate of 10miles per hour. at 2 pm, a bird starts flying towards martin. as soon as the bird gets to martin, it turns back around and flies towards jessica, and continues going back and forth until jessica and martin meet. the bird travels at a constant rate of 45 miles per hour. how far does the bird fly from the time it starts until jessica and martin meet? assume that it takes the bird no time to turn around and fly the other direction.

To run the physics cart, the fan speed of the cart is manipulated. this is the (blank) variable. the cart accelerates due to the speed of the fan. acceleration is therefore the (blank) variable. a “constant” is a parameter that stays the same regardless of the variables. one parameter of the cart that is held constant is the (blank) .

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!

Time remainin52: 42the chart shows data for a moving object. which conclusion is best supported by the information inthe chart? time (s)velocity (m/s