Answer:
Explanation:
See the attached figure . See the forces acting on man pulling up the box .
Man is stationary so net force acting on man is zero .
T + R = Wman
R is the reaction force of the ground of second floor .
R = Wman - T
Answer:
The officer's unit detects this 135-mile-per-hour speed and should subtract the patrol car's 70-mile -per-hour ground speed to get your true speed of 65 miles per hour. Instead, the officer's ground-speed beam fixes on the truck ahead and measures a false 50-mile-per-hour ground speed.
Explanation:
A speedometer or speed meter is a gauge that measures and displays the instantaneous speed of a vehicle. Now universally fitted to motor vehicles, they started to be available as options in the early 20th century, and as standard equipment from about 1910 onwards.
Answer:
1) p₀ = 45000 N / s
, p₀ '= 1800
, b) I = -45000 N s
, I = 1800 Ns
Explanation:
Impulse equals the change in momentum
I = Δp
1) the initial moment of the car
p₀ = M v
p₀ = 1500 30
p₀ = 45000 N / s
the change at the moment is
Δp = 45000
because the end the car is stopped
moment of the person
P₀ ’= m v
p₀ '= 60 30
p₀ '= 1800
D₀ '= 1800
2) of the momentum change impulse ratio
car
I = Δp
I = -45000 N s
person
I = Δpo '
I = 1800 Ns
3) the object that give the momentum to stop the wall motoring
The person is stopped by the impulse given by the car
a) This area is the one that absorbs most of the vehicle impulse
be) If using a safety painter, the time during which the greater force will act, therefore the lessons decrease
c) The air bag helps reduction in the speed of the person relatively quickly.
Answer:
Alloy, metallic substance composed of two or more elements, as either a compound or a solution. The components of alloys are ordinarily themselves metals, though carbon, a nonmetal, is an essential constituent of steel.
Explanation:
Alloys are usually produced by melting the mixture of ingredients. The value of alloys was discovered in very ancient times; brass (copper and zinc) and bronze (copper and tin) were especially important. Today, the most important are the alloy steels, broadly defined as steels containing significant amounts of elements other than iron and carbon. The principal alloying elements for steel are chromium, nickel, manganese, molybdenum, silicon, tungsten, vanadium, and boron have a wide range of special properties, such as hardness, toughness, corrosion resistance, magnetizability, and ductility. Nonferrous alloys, mainly copper–nickel, bronze, and aluminum alloys, are much used in coinage. The distinction between an alloying metal and an impurity is sometimes subtle; in aluminum, for example, silicon may be considered an impurity or a valuable component, depending on the application, because silicon adds strength though it reduces corrosion resistance.
Answer:
a) The Energy added should be 484.438 MJ
b) The Kinetic Energy change is -484.438 MJ
c) The Potential Energy change is 968.907 MJ
Explanation:
Let 'm' be the mass of the satellite , 'M'(6×
be the mass of earth , 'R'(6400 Km) be the radius of the earth , 'h' be the altitude of the satellite and 'G' (6.67×
N/m) be the universal constant of gravitation.
We know that the orbital velocity(v) for a satellite -
v=
[(R+h) is the distance of the satellite from the center of the earth ]
Total Energy(E) = Kinetic Energy(KE) + Potential Energy(PE)
For initial conditions ,
h =
= 98 km = 98000 m
∴Initial Energy (
) =
m
+
Substituting v=
in the above equation and simplifying we get,
= 
Similarly for final condition,
h=
= 198km = 198000 m
∴Final Energy(
) = 
a) The energy that should be added should be the difference in the energy of initial and final states -
∴ ΔE =
- 
=
(
-
)
Substituting ,
M = 6 ×
kg
m = 1036 kg
G = 6.67 × 
R = 6400000 m
= 98000 m
= 198000 m
We get ,
ΔE = 484.438 MJ
b) Change in Kinetic Energy (ΔKE) =
m[
-
]
=
[
-
]
= -ΔE
= - 484.438 MJ
c) Change in Potential Energy (ΔPE) = GMm[
-
]
= 2ΔE
= 968.907 MJ