1. Write T if the statement is true or F if it is false. • Force is that which is capable of changing the state of movement of a body.
()
• For a body to be at rest, forces of equal magnitude must act, but in opposite directions. ()
• The force exerted on a rope is that of friction. ()
• When an object is thrown into the air, only the gravitational force acts. ()
• If a body is in balance and an external force acts on it, it is not altered. ()

If babies are consistently placed on their backs without any restrictions, what will happen to their development? a. they suffer from weakness in certain muscle groups. b. their ability to roll over, crawl, and eventually walk is hindered. c. they suffer brain damage from the pressure on the back of the head. d. they learn to roll over, crawl, and eventually walk on their own.

How are the causes of the problems viewed? medical model public health model human services model. what is a method of treatment? medical model public health model human service modelj

[120 total points] (public health) in one of the largest human experiments ever conducted, in 1954 a randomized controlled trial was run to see whether a vaccine developed by a doctor named jonas salk was effective in preventing paralytic polio. a total of 401,974 children (ages 6–9), chosen to be representative of those who might be susceptible to the disease, were randomized to two groups: 200,745 children (the control group c) were injected with a harmless saline solution (a placebo) and the other 201,229 children (the treatment group t) were injected with salk’s vaccine.what was the point of giving saline solution to the children who didn’t get the vaccine? explain briefly.