Ask question

Ask question

All categories

3 years ago

6

A student, starting from rest, slides down a water slide. On the way down, a kinetic frictional force (a nonconservative force)

acts on her. The student has a mass of 73 kg, and the height of the water slide is 11.8 m. If the kinetic frictional force does -5.5 × 103 J of work, how fast is the student going at the bottom of the slide?

1 answer:

salantis [7]3 years ago

3 0

Answer:

<em>The velocity with which the student goes down the bottom of glide is 12.48m/s.</em>

Explanation:

The Non conservative force is defined as a force which do not store energy or get he energy dissipate the energy from the system as the system progress with the motion.

Given are

<em> mass of the student 73 kg</em>

<em> height of water glide 11.8 m</em>

<em> work done as -5.5*10³ J</em>

Have to find speed at which the student goes down the glide.

According to<em> Law of Conservation of energy</em>,

K.E =P.E+Work Done

mv²/2=mgh +W

Rearranging the above eqn for v

v = √2(gh+W/m)

Substituting values,

V = 12.48 m/s.

<em>The velocity with which the student goes down the bottom of glide is 12.48m/s.</em>

You might be interested in

If a 2kg ball rolls down a ramp that is 15 meters long in 25 seconds, what is the

77julia77 [94]

Answer:

1.968504 ft/s

7 0

3 years ago

A friend waves & yells at you. If the sound took 3.20 seconds to reach you and the speed of sound is 340 m/s,

xeze [42]

Answer:

1088 m

Explanation:

3.00 seconds times by 340 =1020+68=1088

5 0

3 years ago

An Atwood machine consists of two masses, mA = 6.8 kg and mB = 8.0 kg , connected by a cord that passes over a pulley free to ro

Lisa [10]

To solve this problem it is necessary to apply the concewptos related to Torque, kinetic movement and Newton's second Law.

By definition Newton's second law is described as

F= ma

Where,

m= mass

a = Acceleration

Part A) According to the information (and as can be seen in the attached graph) a sum of forces is carried out in mass B, it is obtained that,

$\sum F = m_b a$

$m_Bg-T_B = m_Ba$

$T_B = m_Bg-m_Ba$

In the case of mass A,

$\sum F = m_A a$

$T_A = m_Ag-m_Aa$

Making summation of Torques in the Pulley we have to

$\sum\tau = I\alpha$

$T_BR_0-T_AR_0=I\alpha$

$T_B-T_A=I\frac{a}{R^2_0}$

Replacing the values previously found,

$(m_Bg-m_Ba )-(m_Ag-m_Aa )=I\frac{a}{R^2_0}$

$(m_B-m_A)g-(m_B+m_A)a=I\frac{a}{R^2_0}$

$a = \frac{(m_B-m_A)g}{\frac{I}{R_0^2}+(m_B+m_A)}$

$a = \frac{(m_B-m_A)g}{\frac{MR^2_0^2/2}{R_0^2}+(m_B+m_A)}$

$a =\frac{(m_B-m_A)g}{\frac{M}{2}+(m_B+m_A)}$

Replacing with our values

$a =\frac{(8-6.8)(9.8)}{\frac{0.8}{2}+(8+6.8)}$

$a=0.7736m/s^2$

PART B) Ignoring the moment of inertia the acceleration would be given by

$a' =\frac{(m_B-m_A)g}{(m_B+m_A)}$

$a' =\frac{(8-6.8)(9.8)}{(8+6.8)}$

$a' = 0.7945$

Therefore the error would be,

$\%error = \frac{a'-a}{a}*100$

$\%error = \frac{0.7945-0.7736}{0.7736}*100$

$\%error = 2.7%$

8 0

3 years ago

A ball is fixed to the end of a string, which is attached to the ceiling at point P. As the drawing shows, the ball is projected

Ganezh [65]

Answer:

The ball's initial kinetic energy

The ball comes to a stop at B. At this point its initial kinetic energy is converted into potential energy

Explanation:

A ball is fixed to the end of a string, which is attached to the ceiling at point P. As the drawing shows, the ball is projected downward at A with the launch speed v0. Traveling on a circular path, the ball comes to a halt at point B. What enables the ball to reach point B, which is above point A? Ignore friction and air resistance.

From conservation of energy which states that energy can neither be created nor be destroyed, but can be transformed from one form to another.

Ki+Ui=Kf+Uf

Ki=initial kinetic energy

Ui=initial potential energy

Kf=final kinetic energy

Uf=final potential energy

we know that $\frac{1}{2} mu^{2} +mgha=\frac{1}{2} mv^{2} +mghb$

m=mass of the ball

ha=downward height a

hb=upward height b

u=initial velocity u

v=final velocity v, which is 0

g=acceleration due to gravity

v=0 at final velocity

1/2mu^2+mgha=0+1/2mv^2

ha=hb+Ki/mh

From the above equation, we can conclude that the ball's initial kinetic energy is responsible for making the ball reach point B.

Point B is higher than point A from the motion gained by the ball

3 0

4 years ago

There is much volcanic activity in Iceland, and the country straddles the Mid-Atlantic Ridge. Therefore, Iceland is situated ___

PSYCHO15rus [73]

Divergent plate limits
These plates can be said to be disparate staying away from the nearest plate with respect to area. This usually above the rising waters of the ocean waters . The rising current moves up on the base of the lithosphere, lifting it and streaming horizontally underneath it

4 0

4 years ago