Answer:
96%
Explanation
Let A the total area of the galaxy, is modeled as a disc:
A = πR^2 = π (25 kpc)^2
And let a be the area that astronomers are able to see:
a = πr^2 = π(5 kpc)^2
The percentage that can be seen is equal to 100 times the ratio of the areas, of the galaxy and the "visible" part:
P = 100 a/A = (5/25)^2 = 100/25 = 4%
Therefore, the percentage of the galaxy not included, i.e. not seen is:
(100-4)% = 96%
No
For example a rock was broken into one big and one little piece. The properties of these 2 pieces are still the same even though they have different shapes.
Answer:
Shown by explanation;
Explanation:
The heat of the sample = mass ×specific heat capacity of the sample × temperature change(∆T)
Assumption;I assume the mass of the samples are : 109g and 192g
∆T= 30.1-21=8.9°c.
The heat of the samples are for 109g are:
0.109 × 4186 × 8.9 =4060.84J
For 0.192g are;
∆T= 67-30.1-=36.9°c
0.192 × 4186×36.9=29656.97J
Answer:
Explanation:
A
35 N Small Dog <=======BONE=========> Bigger Dog 42 N
B
Fnet = Large Dog - small dog The forces are subtracted because they are acting in opposite Directions.
Fnet = 42 - 35
Fnet = 7 N
C
m = 2.5 kg
F = 7 N
a = ?
F = m * a
7 = 2.5 a
a = 7 / 2.5
a = 2.8 m/s^2
Before going to solve this question first we have to understand specific heat capacity of a substance .
The specific heat of a substance is defined as amount of heat required to raise the temperature of 1 gram of substance through one degree Celsius. Let us consider a substance whose mass is m.Let Q amount of heat is given to it as a result of which its temperature is raised from T to T'.
Hence specific heat of a substance is calculated as-
![c= \frac{Q}{m[T'-T]}](https://tex.z-dn.net/?f=c%3D%20%5Cfrac%7BQ%7D%7Bm%5BT%27-T%5D%7D)
Here c is the specific heat capacity.
The substance whose specific heat capacity is more will take more time to be heated up to a certain temperature as compared to a substance having low specific heat which is to be heated up to the same temperature.
As per the question John is experimenting on sand and water.Between sand and water,water has the specific heat 1 cal/gram per degree centigrade which is larger as compared to sand.Hence sand will be heated faster as compared to water.The substance which is heated faster will also cools faster.
From this experiment John concludes that water has more specific heat as compared to sand.