Answer: D(t)= 50(4/5)^t
Explanation: If 1/5 of the temperature difference is lost each minute, that means 4/5 of the difference remains each minute. So each minute, the temperature difference is multiplied by a factor of 4/5 (or 0.8).
If we start with the initial temperature difference, 50° Celsius, and keep multiplying by 4/5, this function gives us the temperature difference t minutes after the cake was put in the cooler.
Answer:
The frequency of sound wave created by trumpet is 437.5Hz
Explanation:
Given
the speed of sound wave = 350 m
the wavelength of sound wave = 0.8 m
the frequency of sound wave = ?
All the waves have same relationship among wavelength, frequency and speed, which is given by the equation:
v = fλ, where
v is speed of the wave
f is frequency of the wave
λ is wavelength of the wave
therefore frequency of sound wave is given by
f = v/λ
= 350m
/0.8m
= 437.5
= 437.5Hz (since 1
= 1 Hz (Hertz)
Hence the frequency of sound wave created by trumpet is 437.5Hz
Answer:
Explanation:
In a L C R circuit, the average power is given by

As given in the question
CosФ = R / Z
And we know that

So


Answer:
Capacitive reactance of the capacitor is 68 ohms
Explanation:
It is given that,
Capacitance, 
Frequency, 
Capacitive reactance is given by :



or

So, the capacitive reactance of the capacitor is 68 ohms. Hence, this is the required solution.
Answer:
d = 1.954 Km
Explanation:
given,
total distance, D = 2.5 Km
in stretch A to B =
speed = 99 Km/h = 99 x 0.278 = 27.22 m/s time =t
in stretch B to C
time = 3.4 s
In stretch C to D
speed = 48 Km/h = 48 x 0.278 = 13.34 m/s time =t
we know,
distance = speed x time
distance of BC
using equation of motion
v = u + a t
27.22 = 13.34 - a x 3.4
a = 4.08 m/s²
uniform deceleration is equal to 4.08 m/s²
distance traveled in BC


s = 68.94 m

3000 = 27.5 t + 68.94 + 13.33 t
40.83 t = 2931.06
t = 71.79 s
distance travel in AB
distance = s x t
d = 27.22 x 71.79
d = 1954 m
d = 1.954 Km
distance between A and B is equal to 1.954 Km.