Answer:
One boys rate is "r" and the other's is (r+10)
the distance they cover is 240 miles in 3 hours
3r + 3*(r+10) = 240
6r + 30 = 240
6r = 210
r = 35 mph and the faster car is
r + 10 = 45 mph
Red or violet is the color with the most energetic photons!! Hope this helped!!
Answer:
(a) 2 (b) 4 (c) 4
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
Rules for significant figures:
- Digits from 1 to 9 are always significant and have infinite number of significant figures.
- All non-zero numbers are always significant. For example: 654, 6.54 and 65.4 all have three significant figures.
- All zero’s between integers are always significant. For example: 5005, 5.005 and 50.05 all have four significant figures.
- All zero’s preceding the first integers are never significant. For example: 0.0078 has two significant figures.
- All zero’s after the decimal point are always significant. For example: 4.500, 45.00 and 450.0 all have four significant figures.
- All zeroes used solely for spacing the decimal point are not significant. For example : 8000 has one significant figure.
As per question,
0.000054 has 2 significant figures.
3.001 x 10⁵ has 4 significant figures.
5.600 has 4 significant figures.
Answer:
(d) Water has a high specific heat.
Explanation:
At night, when the temperature of earth goes down due to loss of heat , the temperature of water is lost slowly and temperature of land is lost fast because of high specific heat of water . Water loses as well as gains temperature comparatively slowly due to its high specific heat .
During daytime when earth gains heat , the temperature of land rises more rapidly than water so water appears cool even during daytime when land becomes hotter . It is also due to high heat holding capacity of water or due to high specific heat of water .
'Density' is defined as (mass) / (volume). You need enough information to be able to measure or calculate the mass and the volume of the object.
