In an inelastic collision, only momentum is conserved, while energy is not conserved.
1) Velocity of the nail and the block after the collision
This can be found by using the total momentum after the collisions:

where
m=0.1 kg is the mass of the nail
M=10 kg is the mass of the block of wood
Rearranging the formula, we find

, the velocity of the nail and the block after the collision:

2) The velocity of the nail before the collision can be found by using the conservation of momentum. In fact, the total momentum before the collision is given only by the nail (since the block is at rest), and it must be equal to the total momentum after the collision:

Rearranging the formula, we can find

, the velocity of the nail before the collision:
Answer:
we can say here that | v² - u² | is the same for upward as for downward and change in the speed is different here so | v - u | same whenever rock travel up, down for same time and not same distances
Explanation:
given data
base = 3.60 m
speed u = 8 m/s
height = 1.70 m
to find out
check change in speed
solution
we know here formula for v that is
v² = u² - 2gh ............1 for upward speed
v² = u² + 2gh ............2 for projected speed
so here put all value and find v with h = 3.60 - 1.70 = 1.9 m
v² = 8² - 2(9.8) 1.9 = 26.76
v² = 8² + 2(9.8) 1.9 = 101.24
v = 5.173 m/s ..............3
v = 10.061 m/s ...................4
so change in speed form 3 and 4 equation
change in speed = v - u = 8 - 5.173 = 2.827 m/s .................5
change in speed = v - u = 10.061 - 8 = 2.061 m/s ..................6
so now we can say here that | v² - u² | is the same for upward as for downward and change in the speed is different here so | v - u | same whenever rock travel up, down for same time and not same distances
To determine the amount in grams of the iron, we need data on the density of iron. From literature, it has a value of <span>p=7.9 g/cm3. We simply multiply the volume to the density. We do as follows:
mass = 3.70 (7.9) = 29.23 g Fe
Hope this answers the question. Have a nice day.</span>