Answer:
Because the mechanical advantage of the machine is affected by friction and weight but velocity ratio is not. So, mechanical advantage is less than velocity rate. Thus, the machine's efficiency is less than 100% and can't be a perfect machine
Oxygen is a gas a room temperature.
Answer: True
A water pump
belong to a positive displacement pump that provides constant flow of water at
fixed speed, regardless of changes in the counter pressure. The two main types
of positive displacement pump are rotary pumps and reciprocating pumps.
Moreover, water
pump is a reciprocating positive displacement pump that have an expanding
cavity on the suction side and a decreasing cavity on the discharge side. In
water pumps, the liquid flows into the pumps as the cavity on the suction side
expands and then the liquid flows out of the discharge as the cavity collapses
providing water in a pail.
With constant angular acceleration
, the disk achieves an angular velocity
at time
according to

and angular displacement
according to

a. So after 1.00 s, having rotated 21.0 rad, it must have undergone an acceleration of

b. Under constant acceleration, the average angular velocity is equivalent to

where
and
are the final and initial angular velocities, respectively. Then

c. After 1.00 s, the disk has instantaneous angular velocity

d. During the next 1.00 s, the disk will start moving with the angular velocity
equal to the one found in part (c). Ignoring the 21.0 rad it had rotated in the first 1.00 s interval, the disk will rotate by angle
according to

which would be equal to

Answer:
Por ela ter batido na trave, não tem como voltar 2x mais forte, por que toda ação correspondente a uma reação de igual intensidade, mas que atua no sentido oposto
Explanation: