Answer:
0.872<em>m/s</em>
Explanation:
Tangential velocity is given by the formula,

In the question given,
radius= 25meters
time= 180secs
pie= 3.14
number of laps= 1
The magnitude of tangential velocity equals;

<em>v </em>= 157<em>m</em>/180<em>secs</em>
Therefore, the magnitude of the tangential velocity
=0.872<em>m/secs</em>
Answer:
a)
b)
c) 0 J/K
d)S= 61.53 J/K
Explanation:
Given that
T₁ = 745 K
T₂ = 101 K
Q= 7190 J
a)
The entropy change of reservoir 745 K

Negative sign because heat is leaving.

b)
The entropy change of reservoir 101 K


c)
The entropy change of the rod will be zero.
d)
The entropy change of the system
S= S₁ + S₂
S = 71.18 - 9.65 J/K
S= 61.53 J/K
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
I think WA in friction means Water Absorption.
Answer:
<em>The rebound speed of the mass 2m is v/2</em>
Explanation:
I will designate the two masses as body A and body B.
mass of body A = m
mass of body B = 2m
velocity of body A = v
velocity of body B = -v since they both move in opposite direction
final speed of mass A = 2v
final speed of body B = ?
The equation of conservation of momentum for this system is
mv - 2mv = -2mv + x
where x is the final momentum of the mass B
x = mv - 2mv + 2mv
x = mv
to get the speed, we divide the momentum by the mass of mass B
x/2m = v = mv/2m
speed of mass B = <em>v/2</em>