What is the mass of an object accelerating at 10 m/s2 when a force of 10 N is applied?

Anaesthesia & Intensive Care Medicine

Volume 6, Issue 9, 1 September 2005, Page 294

Force, mass and acceleration

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https://doi.org/10.1383/anes.2005.6.9.294

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Abstract

Force, mass and acceleration are everyday words but often used inaccurately. Force is a physical influence, which when applied to an object causes it to accelerate in the direction from which it was applied. Mass is the amount of matter in an object and is expressed in kilograms. Acceleration is the rate of change of velocity of an object in the same straight line of the unbalanced force. When forces become balanced, there is no net force and therefore no movement. Newton’s second law links these three terms and concerns the effect that an unbalanced force has on the motion of an object. It states that the rate of change of velocity of an object is directly proportional to the force applied and takes place in the direction of the force. It is summarized by the equation: Force (N) = mass (kg) × acceleration (m/s2). Thus, an object of constant mass accelerates in proportion to the force applied. Gravity is the variable force of attraction between any two objects. All matter possesses gravitational ‘pull’ towards other matter. The amount of gravity between two objects is dependent on their mass and the distance between their centres. The word ‘weight’ in its proper context refers to the downward vertical force exerted on an object as a result of the earth’s gravity. An object with greater mass is therefore subjected to a greater gravitational force (i.e. it has greater weight).

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.

just did the assignment and the answer was #1 +2 n