Answer:
the answers the correct one is: the time increases
Explanation:
When an insulating material is placed in the cavity of a wall the thermal conductivity of the system increases, therefore the temperature changes take longer.
P= dQ / dt = K A dT / dx
when placing insulation the value of k is less
When reviewing the answers the correct one is: the time increases
Answer:
11.) g = 3.695 m/s^2
12.) g = 8.879 m/s^2
13.) E = 8127 N/C
Explanation:
11.) Given that the
Mercury mass M = 3.3 × 10^23kg
Radius r = 2.44 ×10^6 m
Gravitational constant G = 6.67408 × 10^-11 m3kg-1 s^-2
Gravitational field strength g can be calculated by using the formula below
g = GM/r^2
Substitutes all the parameters into the formula
g = (6.67408 × 10^-11 × 3.3 × 10^23)/(2.44×10^6)^2
g = 2.2×10^13/5.954×10^12
g = 3.695 m/s^2
12.) Given that the
Venus mass M = 4.87×10^24kg
Radius r = 6.05 × 10^6 m
Using the same formula for gravitational field strength g
g = GM/R2
Substitute all the parameters into the formula
g = (6.67408 × 10^-11 × 4.87×10^24)/(6.05×10^6)^2
g = 3.25×10^14/3.66×10^13
g = 8.879 m/s^2
13.) Given that the
Charge = 2.26 nC = 2.26×10^-9
Distance d = 0.05m
Electric field strength E can be calculated by using the formula below
E = Kq/d^2
Where
K = electrostatic constant 8.99 × 10^9 Nm2/C2
Substitutes all the parameters into the formula
E = (8.99 × 10^9 × 2.26×10^-9)/0.05^2
E = 20.3174/2.5×10^-3
E = 8126.96 N/C
Answer:
Explanation:
a )
In space due to weightlessness both astronaut and her oxygen tank will float .
when she throws the tank away from spacecraft , she will have a velocity in opposite direction ie towards the spacecraft . This happens due to conservation of momentum . She creates a momentum away so that she can get a momentum towards the spaceship.
So
m₁ v₁ = m₂v₂
12 x 8 = ( 87 - 12 ) x v₂
v₂ = 1.28 m /s
Time allowed = 2 x 60
= 120 s
So maximum distance upto which she can remain away from spacecraft
= 120 x 1.28
= 153 m .
b )
The Newton's law which explains the theory behind it is "third law of motion" . This law gives law of conservation of momentum .
The car undergoes an acceleration <em>a</em> such that
(45.0 km/h)² - 0² = 2 <em>a</em> (90 m)
90 m = 0.09 km, so
(45.0 km/h)² - 0² = 2 <em>a</em> (0.09 km)
Solve for <em>a</em> :
<em>a</em> = (45.0 km/h)² / (2 (0.09 km)) = 11,250 km/h²
Ignoring friction, the net force acting on the car points in the direction of its movement (it's also pulled down by gravity, but the ground pushes back up). Newton's second law then says that the net force <em>F</em> is equal to the mass <em>m</em> times the acceleration <em>a</em>, so that
<em>F</em> = (4500 kg) (11,250 km/h²)
Recall that Newtons (N) are measured as
1 N = 1 kg • m/s²
so we should convert everything accordingly:
11,250 km/h² = (11,250 km/h²) (1000 m/km) (1/3600 h/s)² ≈ 0.868 m/s²
Then the force is
<em>F</em> = (4500 kg) (0.868 m/s²) = 3906.25 N ≈ 3900 N
