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4 years ago

An upward moving object must be experiencing (or at least usually does experience) an upward force?

1 answer:

7 0

That's false. Think about a stone or a baseball, during the first
several seconds after you tossed it straight up, before it reaches
its maximum height and starts to come down again.
There's no upward force on it during that time.

Also, after a roller coaster reaches the top of the FIRST hill, there's
no upward force on it for the whole rest of the ride, even though it
coasts up many more hills.

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You are working with a team that is designing a new roller coaster-type amusement park ride for a major theme park. You are pres

Dominik [7]

Answer:

<em>The required constant friction force for the last 20 m is 6,862.8 N</em>

Explanation:

<u>Energy Conversion</u>

There are several ways the energy is manifested in our physical reality. Some examples are Kinetic, Elastic, Chemical, Electric, Potential, Thermal, Mechanical, just to mention some.

The energy can be converted from one form to another by changing the conditions the objects behave. The question at hand states some types of energy that properly managed, will make the situation keep under control.

Originally, the m=220 kg car is at (near) rest at the top of a h=101 m tall track. We can assume the only energy present at that moment is the potential gravitational energy:

$E_1=mgh=220\cdot 9.8\cdot 101=217,756\ J$

For the next x1=230 m, a constant friction force Fr1=350 N is applied until it reaches ground level. This means all the potential gravitational energy was converted to speed (kinetic energy K1) and friction (thermal energy W1). Thus

$E_1=K_1+W_1$

We can compute the thermal energy lost during this part of the motion by using the constant friction force and the distance traveled:

$W_1=F_{r1}\cdot x_1=350\cdot 230=80,500\ J$

This means that the kinetic energy that remains when the car reaches ground level is

$K_1=E_1-W_1=217,756\ J-80,500\ J=137,256\ J$

We could calculate the speed at that point but it's not required or necessary. That kinetic energy is what keeps the car moving to its last section of x2=20 m where a final friction force Fr2 will be applied to completely stop it. This means all the kinetic energy will be converted to thermal energy:

$W_2=F_{r2}\cdot x_2=137,256$

Solving for Fr2

$\displaystyle F_{r2}=\frac{137,256}{20}=6,862.8\ N$

The required constant friction force for the last 20 m is 6,862.8 N

3 0

3 years ago

Three identical capacitors are connected in series across a potential source (battery). If a charge of Q flows into this combina

inessss [21]

Answer:

C.Q/3

Explanation:

The total capacitances in series

1/C=1/C1+1/C2+1/C3

=1 /C+1/C+1/C

3/C

Ctotal=C/3

Charge in each capacitances

1/3*Q

Q/3

8 0

3 years ago

In an electroplating process, copper (ionic charge +2e, atomic weight 63.6 g/mol) is deposited using a current of 10.0 A. What m

statuscvo [17]

Answer:

1.974 g

Explanation:

Electrochemical equivalent of copper, z = 0.000329 g/C

I = 10 A

t = 10 minutes = 10 x 60 = 600 seconds

By the use of Farady's law of electrolysis

m = z I t

m = 0.000329 x 10 x 600

m = 1.974 g

5 0

3 years ago

What is the mechanical energy of a 500kg rollercoaster car moving with a speed of 3m/s at the top hill that is 30m high

koban [17]

K.E = 1/2*m*v^2 = 1/2(500)(3)^2 = 2250 J

m*g*h = 500(9.8)(30) = 147000 J

2250 + 147000 = 149250

4 0

3 years ago

What is the CGS unit of current?

tangare [24]

The answer you are looking for is biot.

6 0

3 years ago

Read 2 more answers