Julie wanted to know if adding calcium fertilizer to tomato plants will prevent a disease of tomato plants called blossom-end rot. she used 10 tomato plants. she put 5 plants in a sunny part of the garden and gave each one calcium fertilizer once a week. she placed the other 5 plants in a shady part of the garden and gave them calcium fertilizer twice a week—she thought that since they were in the shade they might need more fertilizer. she then observed the 10 plants for 3 months to see if the fertilizer prevent blossom-end rot. identify and explain one weakness in julie's experimental design.

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!

Which statement is best supported by the information in the chart? wave y is moving the fastest. wave x is moving the fastest. all of the waves are moving at the same speed. all of the waves have the same value of wavelengths per second.

What is the rate of change in a objects position?