Physics, 09.10.2019 09:20 allison9746

Students are experimenting with a substance that they think can be added to soil to increase the number of flowers a certain plant will make. they set up 20 pots of soil, each planted with the same type of seed. they divide the pots into two groups and add 15 drops of the substance to pots in one group and only 10 drops to pots in the other group. after the plants grow for four weeks, the students count how many flowers each plant has made.

what does this experimental investigation lack?

a control group
an independent variable
a dependent variable
a procedure

Answers: 3

Show answers

Another question on Physics

Physics, 21.06.2019 15:20

If a clock aboard a space ship traveling at 0.900 c of the speed of light relative to earth chimes once at the beginning of the hour and again when it reads one hour later, how much time would an observer on earth say elapsed between the two chimes?

Answers: 2

Answer

Physics, 21.06.2019 16:00

28. a stone is projected at a cliff of height h with an initial speed of 42.0 mls directed at angle θ0 = 60.0° above the horizontal. the stone strikes at a, 5.50 s after launching. find (a) the height h of the cliff, (b) the speed of the stone just before impact at a, and (c) the maximum height h reached above the grou

Answers: 1

Answer

Physics, 21.06.2019 23:00

Follow these directions and answer the questions. 1. set up the ripple tank as in previous investigations. 2. bend the rubber tube to form a "concave mirror" and place in the ripple tank. the water level must be below the top of the hose. 3. generate a few straight pulses with the dowel and observe the reflected waves. do the waves focus (come together) upon reflection? can you locate the place where the waves meet? 4. touch the water surface where the waves converged. what happens to the reflected wave? 5. move your finger twice that distance from the hose (2f = c of c, center of the curvature) and touch the water again. does the image (the reflected wave) appear in the same location (c of c)? you may have to experiment before you find the exact location. sometimes it is hard to visualize with the ripple tank because the waves move so quickly. likewise, it is impossible to "see" light waves because they have such small wavelengths and move at the speed of light. however, both are examples of transverse waves and behave in the same way when a parallel wave fronts hit a curved surface.

Answers: 1

Answer

Physics, 22.06.2019 12:00

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.

Answers: 1

Answer

You know the right answer?

Students are experimenting with a substance that they think can be added to soil to increase the num...

Questions