I believe this is right-
for the first question, it should be fluffy
and for the second it should be spot
potential energy is unused
kinetic energy is being used
Answer:
Explanation:
Given
acceleration is given by

where 

Also acceleration is given by








at 





when air drag is neglected maximum height reached is


Answer:
0.4113772 s
Explanation:
Given the following :
Mass of bullet (m1) = 8g = 0.008kg
Initial horizontal Velocity (u1) = 280m/s
Mass of block (m2) = 0.992kg
Maxumum distance (x) = 15cm = 0.15m
Recall;
Period (T) = 2π√(m/k)
According to the law of conservation of momentum : (inelastic Collison)
m1 * u1 = (m1 + m2) * v
Where v is the final Velocity of the colliding bodies
0.008 * 280 = (0.008 + 0.992) * v
2.24 = 1 * v
v = 2.24m/s
K. E = P. E
K. E = 0.5mv^2
P.E = 0.5kx^2
0.5(0.992 + 0.008)*2.24^2 = 0.5*k*(0.15)^2
0.5*1*5.0176 = 0.5*k*0.0225
2.5088 = 0.01125k
k = 2.5088 / 0.01125
k = 223.00444 N/m
Therefore,
Period (T) = 2π√(m/k)
T = 2π√(0.992+0.008) / 233.0444
T = 2π√0.0042910
T = 2π * 0.0655059
T = 0.4113772 s
Answer: 3.21 N


For weight, we will multiply by 

Hence, the rock would weigh 3.21 N.
Answer:
The length of chain she is allowed is 1.169 ft
Explanation:
The given parameters are;
The linear density of the chain = 0.83 lb/ft
The weight limit of the chain she wants = 1.4 lb
The formula for linear density = Weight/length
Therefore, in order to keep the chain below 1.4 lb, we have;
Linear density = Weight/length
Therefore;
The maximum length she wants = Weight/(Linear density)
Which gives;
The maximum length she wants = 1.4 lb/(0.83 lb/ft) =1.169 ft
Therefore;
The length of chain she is allowed = 1.169 ft.