1. Jim is doing a physics experiment on the rate of cooling of solid objects in air. Which of the following is a variable that is not directly part of his experiment, but should be controlled in his experiment?
(Points : 1)
initial temperature to which he heats the solid object <--
temperature of the object with time
time interval over which he makes his measurement
ambient air temperature
Question 2. 2. In William Herschel's experiment that led to the discovery of infrared light, which of the following was his independent variable?
(Points : 1)
ambient temperature
color of light
time of day
amount of sunlight <--
Question 3. 3. Sara is doing a projectile motion experiment in which she rolls a ball off a table and measures how long the ball takes to hit the ground. Which of the following is a potential source of error in her investigations?
(Points : 1)
She rolls the ball from the same height.
She does the experiment with the same equipment, but on different days.
She uses different stopwatches to measure the time. <--
She uses the same ball.
Question 5. 5. What was the purpose of Herschel's extra thermometers in his infrared light experiments?
(Points : 1)
to provide backups in case the thermometer in the light broke
to control for changes in ambient temperature <--
to measure the effect of sunlight on heat
to identify the independent variable