Answer:
C
technically B too but youre teachers not that smart so there you go
<span>When reading a buret, the initial reading should be taken from the top of the glassware and the final volume should still taken at the top. If the buret is completely, the initial volume for most buret would be zero. though, there are some where their initial starts at 50 decreasing to zero.</span>
Explanation:
In order to find out if the keys will reach John or not, we can use the formula of projectile motion to find the maximum height reached by the keys:
H = V²Sin²θ/2g
where,
V = Launch Speed = 18 m/s
θ = Launch Angle = 40°
g = 9.8 m/s²
Therefore,
H = (18 m/s)²[Sin 40°]²/(2)(9.8 m/s²)
H = 6.83 m
Hence, the maximum height that can be reached by the projectile or the keys is greater than the height of John's Balcony(5.33 m).
Therefore, the keys will make it back to John.
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.