Physics, 21.11.2019 19:31 josuealejandro9632

(a) a child slides down a water slide at an amusement park from an initial height h. the slide can be considered frictionless because of the water flowing down it. can the equation for conservation of mechanical energy be used on the child?

(b) is the mass of the child a factor in determining his speed at the bottom of the slide?

(c) the child drops straight down rather than following the curved ramp of the slide. in which case will he be traveling faster at ground level?

following the curved ramp
dropping straight down
same speed in either case

(d) if friction is present, how would the conservation-of-energy equation be modified?

(e) find the maximum speed of the child when the slide is frictionless if the initial height of the slide is 11.5 m. (assume the child is initially at rest.) m/s

Answers: 3

Show answers

Answers

Answer from: vanessagomezcx

(a) Yes

Explanation: the slide is frictionless: this means that there are no non-conservative forces acting on the child, therefore the mechanical energy of the child is conserved.

The mechanical energy is sum of the kinetic energy (K) and the gravitational potential energy (U) of the child:

$E=K+U=\frac{1}{2}mv^2+mgh=const.$

where m is the mass of the child, v is his speed, g is the gravitational acceleration, h is his heigth above the ground.

(b) No

At the beginning of the motion of the child (highest point of the slide), the child is at rest, so its speed is zero: v=0, and all the mechanical energy is just potential energy:

E=U=mgh

where h is the height of the slide.

At the bottom of the slide, the height is zero: h=0, so all the mechanical energy has been converted into kinetic energy:

$E=K=\frac{1}{2}mv^2$

where v is the speed at the bottom of the slide. Since E is conserved, we can equalize the two equations, and we find an expression for v:

$\frac{1}{2}mv^2=mgh\\v=\sqrt{2gh}$

And we see that v does not depend on the mass of the child.

We can repeat the same procedure used in the previous part of the exercise, by using the conservation of energy, and we see again that the final speed of the child at ground level depends only on the height of the slide, h:

$v=\sqrt{2gh}$

Therefore, the child will be travelling at same speed.

(d) $mgh = \frac{1}{2}mv^2 + E_{wasted}$

If friction is present, the mechanical energy is no longer conserved, because part of the energy has been wasted because of the friction. The equation of conservation of energy would become:

$mgh = \frac{1}{2}mv^2 + E_{wasted}$

which means that the initial potential energy at the top of the ramp (mgh) has been converted only partially into kinetic energy ( $\frac{1}{2}mv^2$ ), while part has been wasted because of the frictional force ( $E_{wasted}$ ).

(e) 15.0 m/s

If we apply the formula found at point b), by using h=11.5 m, we can immediately find the speed of the child at the bottom in this situation:

$v=\sqrt{2gh}=\sqrt{2(9.8 m/s^2)(11.5 m)}=15.0 m/s$

Answer from: Quest

Depending on how the continental plates move it can cause a continental scale shift.

Answer from: Quest

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.

Other questions on the subject: Physics

Physics, 22.06.2019 14:30, livagrace

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2

Answers: 1

continue

Physics, 22.06.2019 14:40, hastephens03

According to valence bond theory, which orbitals overlap in the formation of the bond in hf according to valence bond theory, which orbitals overlap in the formation of the bond in hf 2s on h and 2p on f 1s on h and 2s on f 1s on h and 1p on f 1s on h and 2p on f 1s on h and 3p on f

Answers: 3

continue

Physics, 22.06.2019 15:20, ineedhelp2285

Aphoton is absorbed by an electron that is in the n = 3 state of a hydrogen atom, causing the hydrogen atom to become ionized. very far away from the nucleus, the released electron has a velocity of 750,000 m/s. what was the wavelength of the absorbed photon?

Answers: 2

continue

Physics, 22.06.2019 15:30, tiffuuu

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.

Answers: 1

continue

You know the right answer?

(a) a child slides down a water slide at an amusement park from an initial height h. the slide can b...