<h2>The work done = - 2 x 10⁴ J</h2>
Explanation:
In the first case , the volume is kept constant and pressure varies .
In isothermal process , the work done
W₁ = V x ΔP
here V is the volume of gas and ΔP is the change in pressure
Thus W₁ = 0
Because there is no change in volume , therefore displacement is zero .
In second case pressure is constant , but volume changes
Thus W₂ = P x ΔV
here P is the pressure and ΔV is the change in volume
Therefore W₂ = 4 x 10⁵ x 5 x 10⁻² = 2 x 10⁴ J
The total work done W = - 2 x 10⁴ J
Because the work done in compression is negative .
Answer:
1.dr/dt=0.0096cm/s
2. dA/dt=2.19cm^2/s
Explanation:
A spherical balloon is deflating at 10 cm3/s. At what rate is the radius changing when the volume is 1000π cm3 ? What is the rate of change of surface area at this moment?
for this question, we need to analyze the parameters we know
V=volume of the spherical balloon 1000π cm3
volume of the sphere=
1000π=4/3πr^3
dividing both sides by 4
250*3=r^3
r=9.08cm, the radius of the balloon
dv/dt=dv/dr*dr/dt...................................1
dv/dr ,means
V=
dv/dr=4*pi*r^2
dv/dt=10 cm3/s
from equ 1
10=4*pi*9.08^2*dr/dt
10=1036 dr/dt
dr/dt=10/1036
dr/dt=0.0096cm/s
2. to find the rate at which the area is changing we have,
dA/dt=dA/dr*dr/dt
area of a sphere is 4πr^2
differentiate a with respect to r, radius
dA/dr=8πr
dA/dt=8πr*0.0096
dA/dt=8*pi*9.08*0.0096
dA/dt=2.19cm^2/s
is the rate of change of the surface area
#1) the person holding a baby
- holding implies no motion--> no distance--> no work
#2) the car stuck in the snow
- they're trying to get it out which means that there may be some oscillation. so technically a very small amount of work is being done.