-- She went up for 0.4 sec and down for 0.4 sec.
-- The vertical distance traveled in gravity during ' t ' seconds is
D = (1/2) x (g) x (t)²
= (1/2) (9.8 m/s²) (0.4 sec)²
= (4.9 m/s²) x (0.16 s²)
= 0.784 meter ( B )
The given question is incomplete. The complete question is as follows.
The block has a weight of 75 lb and rests on the floor for which 
= 0.4. The motor draws in the cable at a constant rate of 6 ft/sft/s. Neglect the mass of the cable and pulleys.
Determine the output of the motor at the instant 
.
Explanation:
We will consider that equilibrium condition in vertical direction is as follows.
N - W = 0
N = W
or, N = 75 lb
Again, equilibrium condition in the vertical direction is as follows.
= 0
= 
= 30 lb
Now, the equilibrium equation in the horizontal direction is as follows.
or, T = 
= 
= 
= 17.32 lb
Now, we will calculate the output power of the motor as follows.
P = Tv
= 
= 
= 0.189 hp
or, = 0.2 hp
Thus, we can conclude that output of the given motor is 0.2 hp.
I don't know the answer but I do know this
A mantle plume is posited to exist where hot rock nucleates at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust.[3] The currently active volcanic centers are known as "hot spots". In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, was thought to provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain.
Answer:
Explanation:
1 ) the volume of helium in the balloon when fully inflated
= 4/3 π R³
= 4/3 x 3.14 x 5.3³
= 623.3 m³
2 ) force of gravity on the entire system ,but with no people
= (mass of the empty balloon and basket + mass of helium )x g
=( 129 + 623.3 x.18 )x 9.8
= 2363.7 N
3 ) magnitude of the buoyant force on the entire system (but with no people )
( Volume of empty balloon + basket + volume of helium ) density of air x g
( 0.057 + 623.3 ) x 1.23 x 9.8
= 7513.94 N
4 ) magnitude of the force of gravity on each person
Mass of each person x g
= 71 x 9.8
= 695.8 N
