Answer:
773.15K
Explanation:
Temperature is measured in different units, however, the standard or absolute temperature unit is Kelvin (K).
To convert the temperature of a black body, which is 500°C to Kelvin, we use;
T(K) = T(°C) + 273.15
T(K) = 500°C + 273.15
T(K) = 773.15K
Hence, the temperature of the blackbody at 500°C will be 773.15 K for it to radiate twice as much energy per second.
Answer:
This question is incomplete as it lacks options, the options are:
Which change would be the most effective way to improve the validity of this experiment?
A) Increase the number of goldfish in each tank.
B) Increase the daily amount of food for each tank.
C) Create another group that is fed regular fish food.
D) Increase the number of tanks in each treatment group.
The answer is C
Explanation:
According to this question, an experiment is conducted by Trey to determine which fish food causes the most goldfish activity over a period of two weeks. In this experiment, the independent variable is the FISH FOOD which are; Swift Salmon food and Fast Flounder food. Other variables such as type of gold fish, amount of fish food, amount & type of water etc.
One of the ways to improve an experiment, which is lacking in this case is to have a CONTROL GROUP. Based on the fish foods used for each group, it is obvious that all groups in this experiment are experimental. Hence, creating another group that is fed regular fish food will serve as the CONTROL GROUP in order to compare with the experimental groups. This will improve the validity of the experiment.
<u>Answers
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1) B. longitudinal.
2) B. air is cooler than the ground.
<u>Explanation
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Q1
There are two categories of a wave. That is transverse and longitudinal waves. Transverse waves forms crests and troughs while longitudinal forms compressions and rarefaction as they travel. Rarefactions are regions where the wavelengths are longer than other regions.
Q2
As the ray of light moves from an optically less dense to a more dense region it bends towards the normal.
If the sound is bending away from the earth's surface, then the ground must be warmer than the air. As the sound travels it moves from optically dense medium to a less dense medium. For this reason it bends away from the normal. This can only happen when, B. air is cooler than the ground.
Answer: Whenever the temperature is high, the air pressure is low.
Explanation:As the temperature rises, the air gets heated, expands, and becomes lighter. … As a result, the air pressure in such areas decreases.
Answer:
W = 68.6 N
Explanation:
Given that,
Force acting on a right side = 30 N
Mass of the object, m = 7 kg
The force of friction acting on the car = 3 N
We need to find the weight of the object.
The weight of an object is given by :
W = mg
Substitute all the values,
W = 7 × 9.8
W = 68.6 N
So, the weight of the object is 68.6 N.
