Answer:
500 Pa
Explanation:
Convert given units to SI:
100 dyne = 0.001 N
0.02 cm² = 2×10⁻⁶ m²
Pressure = force / area
P = 0.001 N / (2×10⁻⁶ m²)
P = 500 Pa
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
Answer: 24.7 degrees Max
Explanation:
m*g = 3 * 9.8 = 29.4 N. = Wt. of book.
Fp = 29.4*sin A = Force parallel to the
plank.
Fn = 29.4*Cos A = Force perpendicular to
the plank.
Fs = u*Fn = 0.46*29.4*Cos A
Fp-Fs = m*a
29.4*sin A - 0.46*29.4*Cos A = m*0 = 0
29.4*Sin A = 0.46*29.4*Cos A
Sin A = 0.46*Cos A
Divide both sides by Cos A:
Sin A/Cos A = 0.46
Replace Sin A/Cos A with Tan A:
Tan A = 0.46
A = 24.7 degrees Max.