Electroreception is limited to aquatic environments because on here is the resistivity of the medium is low enough for electric currents to be generated as the result of electric fields of biological origin. In air, the resistivity of the environment is so high that electric fields from biological sources do not generate a significant electric current. Electroreceptor are found in a number of species of fish, and in at least one species of mammal, the Duck-Billed platypus.
Answer:633.8 KJ
Explanation:
Given
mass of water
Initial temperature
Final temperature 
Specific heat of water 
=4190 J/kg-k
heat of vaporization
Heat required for process
=heat to raise water temperature from 20 to 100 +Heat to vapourize water completely
Q=mc
Q=
Q=
Q=
Answer:
1.805 mm
Explanation:
Extension in the steel wire = WL_{steel}/AE_{steel}
Extension in the aluminium wire = WL_{Al}/AE_{Al}
Total extension = W/A * (L_{steel}/E_{steel} + L_{Al}/E_{Al})
we have:
W = mg
W = 5 × 9.8
W = 49 N
Area A = π/4 × (0.001)²
= 7.85398 × 10 ⁻⁷ m²
Total extension = W/A * (L_{steel}/E_{steel} + L_{Al}/E_{Al})
Total extension = 49/ 7.85398 × 10 ⁻⁷ ( (1.5/ 200×10⁹) + 1.5/ 70×10⁹))
Total extension = 0.0018048
Total extension = 1.805 mm
Thus, the total extension = the resulting change in the length of this composite wire = 1.805 mm
Answer:
v_f = 6.92 x 10^(4) m/s
Explanation:
From conservation of energy,
E = (1/2)mv² - GmM/r
Where M is mass of sun
Thus,
E_i = E_f will give;
(1/2)mv_i² - GmM/(r_i) = (1/2)mv_f² - GmM/(r_f)
m will cancel out to give ;
(1/2)v_i² - GM/(r_i) = (1/2)v_f² - GM/(r_f)
Let's make v_f the subject;
v_f = √[(v_i)² + 2MG((1/r_f) - (1/r_i))]
G is Gravitational constant and has a value of 6.67 x 10^(-11) N.m²/kg²
Mass of sun is 1.9891 x 10^(30) kg
v_i = 2.1×10⁴ m/s
r_i = 2.5 × 10^(11) m
r_f = 4.9 × 10^(10) m
Plugging in all these values, we have;
v_f = √[(2.1×10⁴)² + 2(1.9891 x 10^(31)) (6.67 x 10^(-11))((1/(4.9 × 10^(10))) - (1/(2.5 × 10^(11)))] 20.408 e12
v_f = √[(441000000) + 2(1.9891 x 10^(30)) (6.67 x 10^(-11))((16.408 x 10^(-12))]
v_f = √[(441000000) + (435.38 x 10^(7))
v_f = 6.92 x 10^(4) m/s
Answer:
The stuntman will not make it
Explanation:
At the bottom of the swing, the equation of the forces acting on the stuntman is:
where:
T is the tension in the rope (upward)
mg is the weight of the man (downward), where
m = 82.5 kg is his mass
is the acceleration due to gravity
is the centripetal force, where
v = 8.65 m/s is the speed of the man
r = 12.0 m is the radius of the circule (the length of the rope)
Solving for T, we find the tension in the rope:
Since the rope's breaking strength is 1000 N, the stuntman will not make it.
