Question

4 a student plants four african violet plants in four identical pots to compare whether and how much they will bloom. he places the pots in four ventilated glass cases with controlled temperature and humidity. he places the first box in 1,200 lumens of light, the second in 1,500 lumens, the third in 1,800 lumens, and the fourth in 2,100 lumens. 3 marks what is not variable in this experiment? a. the temperature b. the ventilation c. the humidity d. all of these above 5 state which of the following provides evidence in support of the big bang theory. 3 marks a. fusion of hydrogen into helium b. redshift of starlight from distant galaxies c. supernova explosion d. gravitational attraction 6 which statement about the resultant force and acceleration of the object when it is at point p is correct? an object moves at constant speed in the circular path shown. 3 marks a. the resultant force is in the direction of arrow z and acceleration is in the direction of y. b. the resultant force and acceleration are in the direction of y. c. the resultant force and acceleration are in the direction of z. d. the resultant force is at p and acceleration are in the direction of x. page 3 of 9 7 scientists are performing an experiment with a new biotin supplement pill to determine its effects on hair and nail growth. the supplement is tested on 100 men and 100 women in the same age range. half of the subjects are given the biotin supplement pill each day for 30 days, and the other half of the subjects are given one placebo pill each day for 30 days. at the end of the 30 - days trial period, the scientists measure the growth of each subjects nails and hair. 3 marks which is an example of the dependent variable in this experiment? a. the 30 - day trial period b. the age of the subjects c. the amount of hair and nail growth per subject d. the type of pill the subject received 8 according to some estimates, it would cost about ten times more to send a crewed mission to mars to collect geologic samples and look fission. some people think that a

Explanation:

Question 4

In an experiment, controlled variables are kept constant. Here, the student places pots in glass cases with controlled temperature, ventilation, and humidity. Only light intensity (lumen) varies. So temperature, ventilation, and humidity are not variable (controlled). Thus, all (A, B, C) are not variable, so the answer is D.

The Big Bang theory's evidence includes redshift of distant galaxies (Hubble's law), showing universe expansion. Hydrogen fusion is in stars, supernova is stellar explosion, gravitational attraction is a force. Redshift supports Big Bang.

For an object in uniform circular motion, resultant force (centripetal force) and acceleration (centripetal acceleration) act towards the center. At point P, direction Z is towards the center. So resultant force and acceleration are in direction Z.

Answer:

D. all of these above

Question 5