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NeTakaya
2 years ago
8

A roller coaster cart of mass m = 223 kg starts stationary at point A, where h1 = 26.8 m and a while later is at B, were h2 = 14

.7 m. The acceleration of gravity is 9.8 m/s 2 . What is the speed of the cart at B, ignoring the effect of friction?
Physics
1 answer:
Tresset [83]2 years ago
4 0

Answer:

vB = 15.4 m/s

Explanation:

Principle of conservation of energy:

Because there is no friction the mechanical energy is conserve

ΔE = 0

ΔE : mechanical energy change (J)

K : Kinetic energy (J)

U: Potential energy (J)

K = (1/2)mv²

U = m*g*h

Where :

m: mass (kg)

v : speed (m/s)

h : hight (m)

Ef - Ei = 0

(K+U)final - (K+U)initial =0

(K+U)final = (K+U)initial

((1/2)mv²+m*g*h)final = ((1/2)mv²+m*g*h)initial , We divided by m both sides of the equation:

((1/2)vB² + g*hB = (1/2 )vA²+ g*hA

(1/2) (vB)² + (9.8)*(14.7) =  0 + (9.8)(26.8 )

(1/2) (vB)² = (9.8)(26.8 ) - (9.8)*(14.7)

(vB)² = (2)(9.8)(26.8 - 14.7)

(vB)² = 237.16

v_{B} = \sqrt{237.16}

vB = 15.4 m/s : speed of the cart at B

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Alekssandra [29.7K]

Answer:

B, C and E

Explanation:

The unit of resistance in the international system is the Ohm, the equation that describes the resistance is:

R=p\frac{l}{S} \\

Where (l) is for lenght of the wire, (S) is the area and (p) its the constant associated to the conductor.

It's related by the Ohm's Law:

R=\frac{V}{I}

3 0
3 years ago
Two masses are attracted by a gravitational force of 7 N.
damaskus [11]

Answer:

The answer to your question is: F  = 0.4375 N. The force will be 16 times lower than with the first conditions.

Explanation:

Data

F = 7 N

F = ?  if the masses is quartered

Formula

F = \frac{Km1m2}{r2}

Process

Normal conditions F = Km₁m₂/r²  = 7              

When masses quartered        F = K(m₁/4)(m₂/4)/r²  = ?

                                                F = K(m₁m₂/16)/r²

                                                F = K(m₁m₂/16r²      = 7/16  = 0.4375 N

3 0
2 years ago
You and a highway patrolman are driving at constant speeds in opposite directions on a straight highway. The patrolman is drivin
kompoz [17]

Answer:  75 mph

Explanation:

The Relative Speed for a mobile is equal to the diference between the object and the observer:

Relative Speed (Rs) = Object's Velocity  - Observer's Velocity

Thinking on those terms, we would need to have a universal observer to do any understandable measurement on daily basics. This is why we all use earth as a Static Observer for every measurement we do everyday.

Using Earth as an observer, the Velocity for the Patrolman is:

Patrolman Velocity (Vp) = 60 mph

Because the radar gun does measure the Relative Speed for the object, which is 135 mph, we need to work with the equation to find the Velocity using Earth as a reference.

Object's Relative Velocity = Object's Velocity - Patrolman's Velocity

Object's Velocity = Object's Relative Velocity + Patrolman's Velocity

We need to keep in mind, the Patrolman is going on the opposite direction. Because of this the sign for his velocity should be negative.

Object's Velocity = 135 mph + ( -60 mph)

Object's Velocity = 135 mph - 60 mph

Object's Velocity = 75 mph

3 0
2 years ago
A shopping cart given an initial velocity of 2.0 m/s undergoes a constant acceleration to a velocity of 13 m/s. What is the magn
olga55 [171]

Answer:

The acceleration is a = 2.75 [m/s^2]

Explanation:

In order to solve this problem we must use kinematics equations.

v_{f} = v_{i} + a*t\\

where:

Vf = final velocity = 13 [m/s]

Vi = initial velocity = 2 [m/s]

a = acceleration [m/s^2]

t = time = 4 [s]

Now replacing:

13 = 2 + (4*a)

(13 - 2) = 4*a

a = 2.75 [m/s^2]

5 0
3 years ago
When water freezes, its volume increases by 9.05%. What force per unit area is water capable of exerting on a container when it
AnnZ [28]

Answer:

The Pressure is 0.20 MPa.

(b) is correct option.

Explanation:

Given that,

Change in volume = 9.05%

{tex]\dfrac{\Delta V}{V_{0}}=0.0905[/tex]

We know that.

The bulk modulus for water

B=0.20\times10^{10}\ N/m^2

We need to calculate the pressure difference

Using formula bulk modulus formula

B=\Delta P\dfrac{V_{0}}{\Delta V}

\Delta P=B\dfrac{\Delta V}{V_{0}}

\Delta P=0.2\times10^{10}\times0.0905

\Delta P=0.2\times10^{6}\ Pa

\Delta P=0.20 MPa

Hence, The Pressure is 0.20 MPa.

6 0
3 years ago
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