The strength of the force of friction depends on two factors; the type of surfaces involves and the force that the surfaces are being push together
Answer:
B. Steam burns the skin worse than hot water because the latent heat of vaporization is released as well.
Explanation:
It is given that both steam and the boiling water when in contact with the skin cools down from 100 to 34 degrees Celsius.
For any substance of mass m, the heat required to change the temperature by
is
(S.I. unit = Joules).
where C, the specific heat capacity is the same and a constant for both the condensed steam and the boiling water.
But, there is a "hidden" energy (heat) released by the steam called latent heat
(given by mL, L = specific latent heat) which allows the phase transition (gas to liquid). While both of them are at the same temperature, their energy (heat) is different, which is why steam causes burns worse than boiling water
solution:
y = v0t + ½at²
1150 = 79t + ½3.9t²
0 = 3.9t² + 158t - 2300
from quadratic equations and eliminating the negative answer
t = (-158 + v158² -4(3.9)(-2300)) / 2(3.9)
t = 11.37 s to engine cut-off
the velocity at that time is
v = v0 + at
v = 79 + 3.9(11.37)
v = 123.3 m/s
it rises for an additional time
v = gt
t = v/g
t = 123.3 / 9.8
t = 12.59 s
gaining more altitude
y = ½vt
y = 123.3(12.59) /2
y = 776 m
for a peak height of
y = 776 + 1150
It's C, with the 2/7/4/6 in front of each reactant and product.
Answer:
This is because, the flywheel has a very large moment of Inertia and hence sudden piston torques have negligible effect on the flywheel, but every piston combined has a significant torque. This smoothens out the vibrations.
Explanation: