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2 years ago

A child pulls a sled up a snow-covered hill. The child does 504 J of work on the sled. If the child walks 15 m

Physics

1 answer:

Juliette [100K]2 years ago

7 0

Answer: F = 33.6 N

Explanation: work = force · distance or W = F·s

Force F = W/s = 504 J/15 m

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HELP THIS IS DUE TODAY PLEASE

Sonja [21]

It’s me again lol you’re questions are simple the formula is given in the triangle
The answer is C 39 hz

Please look at the attached image below for the explanation

5 0

2 years ago

How much heat Q H QH does a heat pump with a coefficient of performance of 2.10 2.10 deliver when supplied with 1.82 kJ 1.82 kJ

valina [46]

The operating coefficient or performance coefficient of a heat pump is the ratio between the heating or cooling provided and the electricity consumed. The higher coefficients are equivalent to lower operating costs. The coefficient can be greater than 1, because it is a percentage of the output: losses, other than the thermal efficiency ratio: input energy. Mathematically can be written as,

$\text{Coefficient of performance} = \frac{\text{Heat extracted}}{\text{Electrical energy supplied}}$

$COP = \frac{Q}{E}\rightarrow Q =COP\times E$

Replacing,

$Q = 2.1\times 1.82kJ$

$Q = 3.822kJ$

Therefore the heat is 3.822kJ

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2 years ago

The density of an object is dependent upon the object’s mass and ---

kotegsom [21]

Answer:Volume

Explanation:

Density = mass/ Volume

7 0

3 years ago

Two particles with masses 2m and 9m are moving toward each other along the x axis with the same initial speeds vi. Particle 2m i

s2008m [1.1K]

Answer:

The final speed for the mass 2m is $v_{2y}=-1,51\ v_{i}$ and the final speed for the mass 9m is $v_{1f} =0,85\ v_{i}$ .

The angle at which the particle 9m is scattered is $\theta = -66,68^{o}$ with respect to the - y axis.

Explanation:

In an elastic collision the total linear momentum and the total kinetic energy is conserved.

<u>Conservation of linear momentum:</u>

Because the linear momentum is a vector quantity we consider the conservation of the components of momentum in the x and y axis.

The subindex 1 will refer to the particle 9m and the subindex 2 will refer to the particle 2m

$\vec{p}=m\vec{v}$

$p_{xi} =p_{xf}$

In the x axis before the collision we have

$p_{xi}=9m\ v_{i} - 2m\ v_{i}$

and after the collision we have that

$p_{xf} =9m\ v_{1x}$

In the y axis before the collision $p_{yi} =0$

after the collision we have that

$p_{yf} =9m\ v_{1y} - 2m\ v_{2y}$

$p_{xi} =p_{xf} \\7m\ v_{i} =9m\ v_{1x}\Rightarrow v_{1x} =\frac{7}{9}\ v_{i}$

then

$p_{yi} =p_{yf} \\0=9m\ v_{1y} -2m\ v_{2y} \\v_{1y}=\frac{2}{9} \ v_{2y}$

<u>Conservation of kinetic energy:</u>

$\frac{1}{2}\ 9m\ v_{i} ^{2} +\frac{1}{2}\ 2m\ v_{i} ^{2}=\frac{1}{2}\ 9m\ v_{1f} ^{2} +\frac{1}{2}\ 2m\ v_{2f} ^{2}$

$\frac{11}{2}\ m\ v_{i} ^{2} =\frac{1}{2} \ 9m\ [(\frac{7}{9}) ^{2}\ v_{i} ^{2}+ (\frac{2}{9}) ^{2}\ v_{2y} ^{2}]+ m\ v_{2y} ^{2}$

Putting in one side of the equation each speed we get

$\frac{25}{9}\ m\ v_{i} ^{2} =\frac{11}{9}\ m\ v_{2y} ^{2}\\v_{2y} =-1,51\ v_{i}$

We know that the particle 2m travels in the -y axis because it was stated in the question.

Now we can get the y component of the speed of the 9m particle:

$v_{1y} =\frac{2}{9}\ v_{2y} \\v_{1y} =-0,335\ v_{i}$

the magnitude of the final speed of the particle 9m is

$v_{1f} =\sqrt{v_{1x} ^{2}+v_{1y} ^{2} }$

$v_{1f} =\sqrt{(\frac{7}{9}) ^{2}\ v_{i} ^{2}+(-0,335)^{2}\ v_{i} ^{2} }\Rightarrow \ v_{1f} =0,85\ v_{i}$

The tangent that the speed of the particle 9m makes with the -y axis is

$tan(\theta)=\frac{v_{1x} }{v_{1y}} =-2,321 \Rightarrow\theta=-66,68^{o}$

As a vector the speed of the particle 9m is:

$\vec{v_{1f} }=\frac{7}{9} v_{i} \hat{x}-0,335\ v_{i}\ \hat{y}$

As a vector the speed of the particle 2m is:

$\vec{v_{2f} }=-1,51\ v_{i}\ \hat{y}$

8 0

3 years ago

6. Which Thanksgiving dish contains the most dietary fiber ? (Corn) (Mashed Potatoes) (Sweet Potatoes) (Pecan Pie)

pashok25 [27]

Answer:

The correct option is;

Sweet Potatoes

Explanation:

The dietary fiber in Corn = 2.7 g per 100 g

The dietary fiber in Mashed Potatoes = 1.3 g per 100 g

The dietary fiber in Sweet Potatoes = 3 g per 100 g

The dietary fiber in Pecan Pie = 2.1 g per 100 g

Therefore, the Thanksgiving dish that contains the most dietary fiber per 100 g is Sweet Potatoes

8 0

3 years ago