Answer:
An organelle is a structure in a cell that has specific jobs to do. Organelles are held in the cytoplasm
Answer:
(a) r = 1.062·R
= 
(b) r = 
(c) Zero
Explanation:
Here we have escape velocity v
given by
and the maximum height given by
Therefore, when the initial speed is 0.241v we have
v = 
so that;
v² = 
v² = 
is then
Which gives
or
r = 1.062·R
(b) Here we have
Therefore we put 
in the maximum height equation to get
From which we get
r = 1.32·R
(c) The we have the least initial mechanical energy, ME given by
ME = KE - PE
Where the KE = PE required to leave the earth we have
ME = KE - KE = 0
The least initial mechanical energy to leave the earth is zero.
Answer:
The work done to get you safely away from the test is 2.47 X 10⁴ J.
Explanation:
Given;
length of the rope, L = 70 ft
mass per unit length of the rope, μ = 2 lb/ft
your mass, W = 120 lbs
mass of the 70 ft rope = 2 lb/ft x 70 ft
= 140 lbs.
Total mass to be pulled to the helicopter, M = 120 lbs + 140 lbs
= 260 lbs
The work done is calculated from work-energy theorem as follows;
W = Mgh
where;
g is acceleration due gravity = 32.17 ft/s²
h is height the total mass is raised = length of the rope = 70 ft
W = 260 Lb x 32.17 ft/s² x 70 ft
W = 585494 lb.ft²/s²
1 lb.ft²/s² = 0.0421 J
W = 585494 lb.ft²/s² = 2.47 X 10⁴ J.
Therefore, the work done to get you safely away from the test is 2.47 X 10⁴ J.
Answer:
t=40s,
Explanation:
If you can swim in still water at 0.5m/s, the shortest time it would take you to swim from bank to bank across a 20m wide river, if the water flows downstream at a rate of 1.5m/s, is most nearly:
from the question the swimmer will have a velocity which is equal to the sum of the speed of the water and the velocity to swi across the bank
Vt=v1+v2
the time is takes to swim across the bank will be
DY=Dv*t
DY=distance across the bank
Dv=ther velocity of the swimmer across the bank
t=20/ 0.5m/s,
t=40s, time it takes to swim across the bank
velocity is the rate of displacement
displacement is distance covered in a specific direction
