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4 years ago

Without friction, what force is needed to maintain a 1,000 kg car in uniform motion for 30 minutes?

1 answer:

6 0

The answer is none. According to the first law of Newton, an object stays at the same speed in the same direction if there are not forces unbalancing the object. Without friction, the car would be moving forever, unless there is another force accelerating or stopping the car.

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How is pure salt obtained from the sea water ?describe in brief

lianna [129]

Answer:

Evaporation

Explanation:

Evaporation

7 0

2 years ago

Read 2 more answers

What is the wavelength of an X-ray photon with energy 8.0 keV (8000 eV)? (1 eV = 1.60 × 10−19 joule.)

katrin2010 [14]

Answer:

Wavelength = 0.15 nm

Frequency = $1939.3939\times 10^{15}Hz$

Explanation:

We have given photon energy E = 8 KeV = 8000 eV

In question it is given that $1eV=1.6\times 10^{-19}J$

So $8000eV=1.6\times 8000\times 10^{-19}=12800\times 10^{-19}j$

Plank's constant $h=6.6\times 10^{-34}js$

We know that photon energy is given by $E=h\nu$

So $12800\times 10^{-19}=6.6\times 10^{-34}\nu$

$\nu =1939.3939\times 10^{15}Hz$

Now wavelength $\lambda =\frac{c}{f}=\frac{3\times 10^8}{1939.3939\times 10^{15}}=0.0015\times 10^{-7}m=0.15nm$

3 0

4 years ago

5. Find the volume of the composite space figure to the nearest whole number.

Dmitry [639]

The shape is missing but let's consider it a semi-cylinder attached to the rectangular prism.
Given:
radius = 4.5 mm
Height = 11 mm 

Volume of cylinder = (1/2)(pi)(4.5)^2(11) (the shape is divided into half)
V = 349.89 mm cubed
Volume of prism = L x W x H
= 9 x 11 x 6
= 594 mm cubed
Total volume of the composite shape = 111.375 + 594
= 943.89 mm cubed
Rounded answer = 944 mm cubed.

6 0

4 years ago

Science and technology are interdependent. Advances in one lead to advances in the other.Give an example of this phenomenon.

Vladimir79 [104]

The development of the microscope, a key innovation in the field of technology, lead to the development of Cell Theory, a key innovation in the field of science.

6 0

3 years ago

There are four springs stretched by the same mass. Spring A stretches 25 cm. Spring B stretches 10 cm. Spring C stretches 100 cm

saul85 [17]

Answer:

spring D stretches the weakest

6 0

2 years ago