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cricket20 [7]
2 years ago
13

A girl is holding a ball as she steps onto a tall elevator on the ground floor of

Physics
1 answer:
koban [17]2 years ago
8 0

Answer:

what a big question I must say

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Train cars are coupled together by being bumped into one another. Suppose two loaded train cars are moving toward one another, t
wolverine [178]

Answer:

final velocity =  0.08585m/s

Explanation:

We are taking train cars as our system. In this system no external force is acting. So we can apply the law of conservation of linear momentum.

The law of conservation of linear momentum states that the total linear momentum of a system remains constant if there is no external force acting on the system. That is total linear momentum before = total linear momentum after

total linear momentum before = linear momentum of first train car + linear momentum of second train car

We know that linear momentum = mv

where,

m = mass

v = velocity

thus,

total linear momentum before = m₁v₁ + m₂v₂

m₁ = mass of first train car = 135,000kg

v₁ = velocity of first train car = 0.305m/s

m₂ = mass of first second car =  100,000kg

v₂ = velocity of second train car =  −0.210m/s

Note: Momentum is a vector. So while adding momentum we should take account of its direction too. Here since second train car is moving in a direction opposite to that of the first one, we have taken its velocity as negative.

total linear momentum before = m₁v₁ + m₂v₂

                                                  = 135,000x0.305 + 100,000x(−0.210)

                                                  = 135,000x0.305 - 100,000x0.210

                                                  = 20,175 kgm/s

Now we have to find total linear momentum after bumping. After the bumping both the train cars will be moving together with a common velocity(say v).

Therefore, total linear momentum after = mv

m = m₁ + m₂ = 135,000 + 100,000 = 235,000

total linear momentum before = total linear momentum after

235,000v = 20,175

v =  \frac{20,175}{235,000}

  = 0.08585m/s

8 0
3 years ago
Read 2 more answers
A plane travels 395,000 meters in 9,000 seconds. What was its speed?
sladkih [1.3K]

When a plane travels 395,000 meters in 9,000 seconds its speed is 395,000 ÷ 9000 = 43.888888 (the 8 repeats) meters per second.

8 0
3 years ago
A car is driven 225 km west and then 98 km southwest (45).
slava [35]
Sum the vector components: Dx = 225* Cos(180)+ 78*Cos(225)= -280.154 km Dy = 225* Sin(180)+ 78*Sin(225) = -55.154 km displacement: Sqrt(Dx^2+Dy^2) = 285.532 km Arctan(Dy/Dx) = 191.137degrees CCW OR: 11.137 degrees South of West
4 0
3 years ago
Read 2 more answers
The roller-coaster car shown in fig. 6-41 (h1 = 45 m, h2 = 16 m, h3 = 26 m), is dragged up to point 1 where it is released from
kirill [66]

There are many ways to solve this but I prefer to use the energy method. Calculate the potential energy using the point then from Potential Energy convert to Kinetic Energy at each points.

PE = KE

From the given points (h1 = 45, h2 = 16, h<span>3  </span>= 26)

Let’s use the formula: 

v2= sqrt[2*Gravity*h1]  where the gravity is equal to 9.81m/s2

v3= sqrt[2*Gravity*(h1 - h3 )] where the gravity is equal to 9.81m/s2

v4= sqrt[2*Gravity*(h1 – h2)] where the gravity is equal to 9.81m/s2

Solve for v2

v2= sqrt[2*Gravity*h1]      

    = √2*9.81m/s2*45m

v2= 29.71m/s

v3= sqrt[2*Gravity*(h1 - h3 )   

    =√2*9.81m/s2*(45-26)

    =√2*9.81m/s2*19 

v3=19.31m/s

v4= sqrt[2*Gravity*(h1 – h2)]        

    =√2*9.81m/s2*(45-16)

    =√2*9.81m/s2*(29)

v4=23.85m/s

7 0
2 years ago
Calculate the number of molecules of hydrogen and carbon present in 4 g of methane?​
emmasim [6.3K]

Answer: 6.022×10²³ molecules of CH4 which consists of 1 mole of C atoms and 4 moles of H atoms.

4 0
2 years ago
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