Answer:
Kristine is correct
Explanation:
this is because when an ice cube is placed into the warm water, it absorbs the heat from the water in order to melt which lowers the water's temperature.
in Eric's case, a hot cup of tea does not lose its heat because of cold hands. it varies depending on the cup whether it is a good insulator or not. also the heat can be lost through the air as well.
Answer: question 1 is b I believe
Explanation:
every action has an opposite reaction
Answer:
The motion of particles in any object moves randomly I think
Answer:
51 mph
Explanation:
Given: A certain aircraft can fly 612 miles with the wind in 3 hours and travel the same distance against the wind in 6 hours.
Formula: 
Let speed of aircraft be x mph and speed of wind y mph
Aircraft along wind:
Actual speed of aircraft = x + y
Time taken = 3 hours
Distance = 612 miles
Aircraft against wind:
Actual speed of aircraft = x - y
Time taken = 6 hours
Distance = 612 miles
By solving equation (1) and equation (2) and we get
x = 153 mph
y = 51 mph
Hence, The speed of wind will be 51 mph
Answer:
a) dh/dt = -44.56*10⁻⁴ cm/s
b) dr/dt = -17.82*10⁻⁴ cm/s
Explanation:
Given:
Q = dV/dt = -35 cm³/s
R = 1.00 m
H = 2.50 m
if h = 125 cm
a) dh/dt = ?
b) dr/dt = ?
We know that
V = π*r²*h/3
and
tan ∅ = H/R = 2.5m / 1m = 2.5 ⇒ h/r = 2.5
⇒ h = (5/2)*r
⇒ r = (2/5)*h
If we apply
Q = dV/dt = -35 = d(π*r²*h/3)*dt
⇒ d(r²*h)/dt = 3*35/π = 105/π ⇒ d(r²*h)/dt = -105/π
a) if r = (2/5)*h
⇒ d(r²*h)/dt = d(((2/5)*h)²*h)/dt = (4/25)*d(h³)/dt = -105/π
⇒ (4/25)(3*h²)(dh/dt) = -105/π
⇒ dh/dt = -875/(4π*h²)
b) if h = (5/2)*r
Q = dV/dt = -35 = d(π*r²*h/3)*dt
⇒ d(r²*h)/dt = d(r²*(5/2)*r)/dt = (5/2)*d(r³)/dt = -105/π
⇒ (5/2)*(3*r²)(dr/dt) = -105/π
⇒ dr/dt = -14/(π*r²)
Now, using h = 125 cm
dh/dt = -875/(4π*h²) = -875/(4π*(125)²)
⇒ dh/dt = -44.56*10⁻⁴ cm/s
then
h = 125 cm ⇒ r = (2/5)*h = (2/5)*(125 cm)
⇒ r = 50 cm
⇒ dr/dt = -14/(π*r²) = - 14/(π*(50)²)
⇒ dr/dt = -17.82*10⁻⁴ cm/s
