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4 years ago

Mike walks 200 km in 6 hours.he then walks another 100km in 4 hours .what is his average speed?

Physics

1 answer:

kolbaska11 [484]4 years ago

8 0

Average speed is defined as the ratio of total distance covered in total given time

$speed = \frac{distance}{time}$

here we know that total distance that man moved is

$d_1 = 200 km$

$d_2 = 100 km$

so total distance is

$d = d_1 + d_2$

$d = 200 km + 100 km$

$d = 300 km$

now here total time of the motion is

$t_1 = 6 hours$

$t_2 = 4 hours$

total time will be given as

$t = t_1 + t_2$

$t = 6 + 4 = 10 hours$

now by above formula

$v_{avg} = \frac{300}{10}$

$v_{avg} = 30 km/h$

so his average speed is 30 km/h

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Virginia beach is 15 kilometers wide and 50 kilometers long. if 2 cm of rain falls on virginia beach, how many cubic meters of r

icang [17]

Assume that the shape of Virginia beach is rectangular.

Note that
1 km = 10³ m
1 cm = 10⁻² m

The area is
A = (15 km)*(50 km)
= (15 x 10³ m)*(50 x 10³ m)
= 7.5 x 10⁸ m²

Because 2 cm of rain fell, the volume is
V = (7.5 x 10⁸ m)*(2 x 10⁻² m) = 1.5 x 10⁶ m³

Answer: 1.5 x 10⁶ m³

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3 years ago

What is the relationship between the size of a predator population and the size of a prey population

Contact [7]

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3 0

4 years ago

A proton is propelled at 4×106 m/s perpendicular to a uniform magnetic field. 1) If it experiences a magnetic force of 4.8×10−13

tia_tia [17]

Answer:

B = 0.75 T

Explanation:

As we know that the force on a moving charge in magnetic field is given by the formula

$F = qvB$

here we have

$B = \frac{F}{qv}$

here we know that

$F = 4.8 \times 10^{-13} N$

$q = 1.6 \times 10^{-19} C$

$v = 4 \times 10^6 m/s$

now from above equation we have

$B = \frac{4.8 \times 10^{-13}}{(1.6 \times 10^{-19})(4 \times 10^6)}$

$B = 0.75 T$

8 0

3 years ago

We would be more likely to get an accurate measurement of the distance from Earth to a nearby star if we took the angular measur

NeTakaya

Answer:

6 month interval

Explanation:

The distance to a nearby star in theory is more simple than

one might think! First we must learn about the parallax effect. This is the mechanism our eyes use to perceive things at a distance! When we look at the star from the earth we see it at different angles throughout the earth's movement around the sun similar to how we see when we cover on eye at a time. Modern telescopes and technology can help calculate the angle of the star to the earth with just two measurements (attached photo!) Since we know the distance of the earth from the sun we can use a simple trigonometric function to calculate the distance to the star. The two measurements needed to calculate the angle of the star to the earth caused by parallax (in short angle θ) are shown in the second attached photo.

So using a simple trigonometric function $Sin\theta=\frac{r}{d}$ we can solve for d which is the distance of the earth to the star:

$d=\frac{r}{Sin\theta}$

In the first attached photo a picture where r is the distance to the star and the base of the triangle is the diameter of the earth.

8 0

3 years ago

Use Hooke's Law to determine the variable force in the spring problem. A force of 450 newtons stretches a spring 30 centimeters.

ladessa [460]

Answer:

Work Done = 67.5 J

Explanation:

First we find the value of spring constant (k) using Hooke's Law. Hooke's is formulated as:

F = kx

where,

F = Force Applied = 450 N

k = Spring Constant = ?

x = Stretched Length = 30 cm = 0.3 m

Therefore,

450 N = k(0.3 m)

k = 450 N/0.3 m

k = 1500 N/m

Now, the formula for the work done in stretching the spring is given as:

W = (1/2)kx²

Where,

W = Work done = ?

k = 1500 N/m

x = 70 cm - 40 cm = 0.3 m

Therefore,

W = (1/2)(1500 N/m)(0.3 m)²

3 0

3 years ago