Physics, 29.06.2019 08:30 rosezgomez97

Achild and sled with a combined mass of 50.0 kg slide down a frictionless hill that is 7.34 m high. if the sled starts from rest, what is the mechanical energy of the system, and what is the sled's speed at the bottom of the hill?

Answers: 1

Show answers

Answers

Answer from: gigipalacio32

The mechanical energy of the system is 3596.6 J and the speed of sled at the bottom of hill is 11.99 m/s.

Given data:

The mass of child-sled system is, m = 50.0 kg.

The height of system on the hill is, h = 7.34 m.

The mechanical energy of the system at any point is the combination of kinetic energy as well as potential energy of the system at that point.

Mechanical Energy = Kinetic Energy + Potential Energy

$ME =\dfrac{1}{2}mv^{2} +mgh$

Here, v is the speed of system, since child and sled were at rest initially. Then, v = 0 m/s.

Solving as,

$ME =\dfrac{1}{2} \times 50 \times 0^{2} +(50 \times 9.8 \times 7.34)\\\\ME = 3596.6 \;\rm J$

And at the bottom of the hill, the potential energy of the system is zero. Which means,

Mechanical Energy = Kinetic Energy + Potential Energy

Mechanical Energy = Kinetic Energy + 0

$ME = \dfrac{1}{2}mv'^{2}$

Here, v' is the speed of sled at bottom of hill.

Solving as,

$3596.6 = \dfrac{1}{2} \times 50 \times v'^{2}\\\\v' = 11.99 \;\rm m/s$

Thus, we can conclude that the mechanical energy of the system is 3596.6 J and the speed of sled at the bottom of hill is 11.99 m/s.

Learn more about the mechanical energy here;

link

Answer from: ralphmillerrr

1. Mechanical energy of the system: 3597 J

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

E=K+U

However, the sled starts from rest, so the initial kinetic energy is zero: K=0. Therefore, at the top of the hill all the mechanical energy is just potential energy, given by:

U=mgh

where m=50.0 kg is the mass, g=9.8 m/s^2 the acceleration due to gravity and h=7.34 m is the height. Substituting,

E=U=(50.0 kg)(9.8 m/s^2)(7.34 m)=3597 J

2. Sleed's speed at the bottom of the hill: 12.0 m/s

At the bottom of the hill, h=0, so the potential energy has become zero: U=0. However, the mechanical energy must be conserved, so all this energy has been converted into kinetic energy:

E=K=3597 J

The formula for the kinetic energy is:

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

where m=50.0 kg is the mass and v the speed of the sled at the bottom of the hill. Re-arranging the equation, we find v:

$v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(3597 J)}{50.0 kg}}=12.0 m/s$

Answer from: Quest

unbalanced force

explanation:

Answer from: Quest

no sign of dia of fuel cell

Another question on Physics

Physics, 22.06.2019 02:40

If the wheels lock when braking suddenly the vehicle: a: loses traction b: lose steering wheel ability c: gain speed slightly d: gain steering ability

Answers: 1

Answer

Physics, 22.06.2019 03:30

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Answers: 3

Answer

Physics, 22.06.2019 11:30

1. a camcorder has a power rating of 19 watts. if the output voltage from its battery is 7 volts, what current does it use?answer units 2. a 1.5m wire carries a 6 a current when a potential difference of 57 v is applied. what is the resistance of the wire? your

Answers: 2

Answer

Physics, 23.06.2019 03:30

Select the correct lewis structure for fluorine which is group 7a element?

Answers: 1

Answer

You know the right answer?

Achild and sled with a combined mass of 50.0 kg slide down a frictionless hill that is 7.34 m high....

Questions