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3 years ago

Lora (of mass 47.4 kg) is an expert skier. She

Physics

1 answer:

Harrizon [31]3 years ago

6 0

Answer:

Kinetic energy is 242.7 Joule

Explanation:

m = 47.4 kg

v = 3.2m/s²

Now,

K.E. = 1/2 × m × v²

or, K.E. = 1/2 × 47.4 × 3.2²

or, K.E. = 242.7 Joule

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The planet earth consists of land formations, large masses of water, gases in the atmosphere, and living organisms.

andrew-mc [135]

A.
The planet contains matter and energy so it is a system.

8 0

3 years ago

Based on the simple blackbody radiation model described in class, answer the following question. The planets Mars and Venus have

Lera25 [3.4K]

Answer:

The extent of greenhouse effect on mars is $G_m = 87 K$

Explanation:

From the question we are told that

The albedo value of Mars is $A_1 = 0.15$

The albedo value of Mars is $A_2 = 0.15$

The surface temperature of Mars is $T_1 = 220 K$

The surface temperature of Venus is $T_2 = 700 K$

The distance of Mars from the sun is $d_m = 2.28*10^8 \ km = 2.28*10^8* 1000 = 2.28*10^{11} \ m$

The distance of Venus from sun is $d_v = 1.08 *10^{8} \ km = 1.08 *10^{8} * 1000 = 1.08 *10^{11} \ m$

The radius of the sun is $R = 7*10^{8} \ m$

The energy flux is $E = 6.28 * 10^{7} W/m^2$

The solar constant for Mars is mathematically represented as

$T = [\frac{E R^2 (1- A_1)}{\sigma d_m} ]$

Where $\sigma$ is the Stefan's constant with a value $\sigma = 5.6*10^{-8} \ Wm^{-2} K^{-4}$

So substituting values

$T = \frac{6.28 *10^{7} * (7*10^8)^2 * (1-0.15)}{(5.67 *10^{-8}) * (2.28 *10^{11})^2)}$

$T = 307K$

So the greenhouse effect on Mars is

$G_m = T - T_1$

$G_m = 307 - 220$

$G_m = 87 K$

3 0

4 years ago

For this quiz, we shall return to the radio control car track that we visited briefly on the last quiz. The track is 10 meters l

Iteru [2.4K]

Answer:

$v=1.54\,\,metres\,\,per\,\,second$

Explanation:

The given equation is $x=x_0+vt$ where $x_0$ denotes initial time in the stopwatch and $x$ denotes the distance covered by car.

As the judge starts her watch at the instant the car passes the 2.0 meter mark $(x_0=2)$ and the judge reads 3.9 seconds on her stopwatch when the car passes the 8.0 meter mark.

Put $x_0=2,\,,\,x=8\,,\,t=3.9$ in equation $x=x_0+vt$

$8=2+3.9t\\8-2=3.9t\\6=3.9v\\v=\frac{6}{3.9}\\ v=1.54\,\,metres\,\,per\,\,second$

3 0

3 years ago

What two categories do stress fall into?

Mama L [17]

I think the answer is eustress and distress

6 0

3 years ago

Some Physics questions! Please help!

lesantik [10]

1) 260 km/h

Let's use the following convention:

positive x-direction = east

positive y-direction = north

Here we have to find the north component of the velocity's airplane, which means we have to find its y-component.

We can use the formula:

$v_y = v sin \theta$

where

v = 750 km/h is the magnitude of the plane's velocity

$\theta=20.0^{\circ}$ is the angle between the direction of the plane and the positive x-axis

Substituting,

$v_y = (750)(sin 20)=256.5 km/h \sim 260 km/h$

2) $24^{\circ}$ north of east

In order to find the direction of flight, we have to consider that the vector representing the displacement of the plane is the hypothenuse of a right triangle, of which the displacements along the east and north direction are the sides.

Therefore, we have

$v_x = 220 km$ is the displacement towards east

$v_y = 100 km$ is the displacement towards north

Therefore, the angle that gives the direction is given by

$tan \theta = \frac{v_y}{v_x}$

And substituting,

$\theta =tan^{-1}( \frac{100}{200})=24^{\circ}$

and this angle is measured north of east.

7 0

4 years ago