Which of the following would be an example of an uncontrolled experiment? The effect of salt and water being mixed at different temperatures. The effect of water on different metals in a lab. The effect of heat on a plants growth. The effect of the jet streams on weather conditions.

The effect of salt and water being mixed at different temperatures

Explanation:

An uncontrolled experiment is an experiment in which the independent variable is given to all the groups in the experiment. In other words, an uncontrolled experiment is an experiment without a CONTROL GROUP. Note that, a control group is the group that does not receive any experimental treatment.

Based on the given option, the experiment involving the effect of salt and water being mixed at different temperatures would be an example of uncontrolled experiment. This is because the salt and water mixture must be mixed at a particular temperature, which is the independent variable. Hence, one way or the other in this experiment, all the groups will receive the independent variable (different temperatures), making them all experimental groups.

c. newton's third law of motion

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.