The picture isn’t clear so I can’t read the dimensions of the box but I can try my best to guide u through the question.
For part a u need to find the volume of the box as that will equal the volume of sand that can be filled inside.
For this u multiply the height, width and length of the box.
For part b the mass of sand alone will be
=Mass of box + sand - Mass of empty box
=216 - 40
=176 grams
For part c the density of sand can be calculated by the formula
Density= Mass/Volume
So the mass (176g) / volume from part a
For part d u need to know that something will float if it has a lower density than what it is floating in. If the final density of sand that was found in part c is less than the density of gold (19.3 g/cm^3) it will float. Otherwise it will sink.
Hope this helped!
Explanation:
Given:
u = 20 m/s
a = 5 m/s^2
v = 30 m/s
t = ?
Use the first kinematic equation of motion:
v = u + at
t = (v - u)/a = 10/5 = 2 seconds
The angular momentum is defined as,
Acording to this text we know for conservation of angular momentum that
Where 
is initial momentum
is the final momentum
How there is a difference between the stick mass and the bug mass, we define that
Mass of the bug= m
Mass of the stick=10m
At the point 0 we have that,
Where l is the lenght of the stick which is also the perpendicular distance of the bug's velocity
vector from the point of reference (O), and ve is the velocity
At the end with the collition we have
Substituting
Applying conservative energy equation we have
Replacing the values and solving
Substituting
l=\frac{13}{0.54(9.8)}
