Answer:
7.48 x 10⁵ m
Explanation:
g = 7.86 N/kg
M = 5.97 x 10²⁴ kg, R = 6.37 x 10⁶ m.
Find height h
g = GM/(R + h)²
(R + h)² = GM/g = 6.67 x 10⁺¹¹ x 5.97 x 10²⁴ /7.86 = 5.066 x 10¹³
R + h = 7.12 x 10⁶ m
so
h = 7.12 x 10⁶ - 6.37 x 10⁶ = 7.48 x 10⁵ m
Let's be clear: The plane's "395 km/hr" is speed relative to the
air, and the wind's "55 km/hr" is speed relative to the ground.
Before the wind hits, the plane moves east at 395 km/hr relative
to both the air AND the ground.
After the wind hits, the plane still maintains the same air-speed.
That is, its velocity relative to the air is still 395 km/hr east.
But the wind vector is added to the air-speed vector, and the
plane's velocity <span>relative to the ground drops to 340 km/hr east</span>.
Answer:
Choice A: approximately 
, assuming that the two pistons are connected via some confined liquid to form a simple machine.
Explanation:
Assume that the two pistons are connected via some liquid that is confined. Pressure from the first piston:
.
By Pascal's Principle, because the first piston exerted a pressure of 
on the liquid, the liquid will now exert the same amount of pressure on the walls of the container.
Assume that the second piston is part of that wall. The pressure on the second piston will also be . In other words:
.
To achieve a force of 
, the surface area of the second piston should be:
.
Answer: 25 Ohms
Explanation:
From this question, the following parameters are given:
Voltage V = 1.5 v
Current I = 0.03A
From Ohm's law;
V = IR
Where R = resultant resistance of the two resistors.
Substitute V and I into the formula and make resultant R the subject of formula.
1.5 = 0.03 × R
R = 1.5/0.03
R = 50 Ohms
From the question, it is given that Thr two equal resistors are connected in series.
R = R1 + R2
But R1 = R2
50 = 2R1
R1 = 50/2
R1 = 25
R1 = R2 = 25 Ohms
Therefore, the resistors must each have a value of 25 Ohms
