Lizette works in her school’s vegetable garden. Every Tuesday, she pulls weeds for 15 minutes. Weeding seems like a never-ending task. Each time Lizette goes to the garden, there are just as many weeds as the week before! Lizette’s teacher suggests that she use a strong solution of vinegar to kill the weeds. Vinegar is acidic and prevents plants from maintaining homeostasis. Lizette sets up a controlled experiment to test her hypothesis that the solution will kill the weeds without harming nearby vegetables. She plans to spray one group of weeds with the solution and another group of weeds with water as a control.

What variables should Lizette keep the same between the control group of weeds and the sprayed weeds?

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 740 n/m. it is initially at rest on an inclined plane that is at an angle of theta= 26 with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is uk = 0.17. 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. the block's initial mechanical energy is 9.472 j. 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.