There are different options here but all of them work by approximating and assuming.
i) that the boulder is above ground.
ii) that the bottom surface of the boulder is known.
iii) the shape of the boulder is taken into account.
The most accurate way is measuring it by displacement method but the boulder is immovable hence the volume can be calculated by measuring the boulder or a waterproof box to be built around the boulder and calculate the volume occupied by boulder.
All the above methods are estimating methods.
*Another way to find the density is through specific gravity.
S.G = <u>Density</u><u> </u><u>of</u><u> </u><u>object</u>
Density of water
If the material that makes the boulder is known that is if it's stone or a mineral then the specific gravity can be found.
If the boulder is purely rock then S.G lies between 3 - 3.5 and the density of water is known thus the density of the boulder can be found without moving the boulder.
This is what I think after correction and allthe best!
Answer:
Mechanical advantage = 4
Explanation:
Given the following data;
Distance of effort, de = 8m
Distance of ramp, dr = 2m
To find the mechanical advantage;
Mechanical advantage = de/dr
Substituting into the equation, we have;
Mechanical advantage = 8/2
Mechanical advantage = 4
Tan = opposite/adjacent
= 20/15
=4/3
<u>Answer:</u>
Mass of C in 3.40 g of HCN =1.51 gram.
<u>Explanation:</u>
Mass of sample of HCN = 7.99 g
Mass of H in 7.99 g of HCN = 0.296 g
Mass of N in 7.99 g of HCN = 4.14 g
Mass of C in 7.99 g of HCN = (7.99-0.296-4.14) = 3.554 g
Now mass of HCN = 3.40 g
Mass of C in 3.40 g of HCN = 
So mass of C in 3.40 g of HCN =1.51 gram.
Answer:
b) Springs oscillate with the same frequency,
Explanation:
expression for frequency of vibration of mass hanging from a spring is given as follows
f = 
k is force constant of spring and m is mass vibrating .
In the present case, if mass stretches the spring by x and remains balanced
mg = k x

g and x are same for both cases
will also be same for both cases .
Hence frequency of vibration will also be same for both the balls .