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2 years ago

7

a 10kg box car rolls at 6m/s and crashes into a 20kg box car that is at rest. After the crash, both cars are stuck together. wha

t is their velocity?

1 answer:

Goshia [24]2 years ago

5 0

Answer:

Their velocity is 0m/s because the first box was only 10 kg and the second box was double the weight

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Hello please help i’ll give brainliest

malfutka [58]

Acceleration is the rate of change in an object's velocity

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2 years ago

Calculate the self-inductance (in mH) of a 45.0 cm long, 10.0 cm diameter solenoid having 1000 loops. mH (b) How much energy (in

Karo-lina-s [1.5K]

Answer:

(a) The self inductance, L = 21.95 mH

(b) The energy stored, E = 4.84 J

(c) the time, t = 0.154 s

Explanation:

(a) Self inductance is calculated as;

$L = \frac{N^2 \mu_0 A}{l}$

where;

N is the number of turns = 1000 loops

μ is the permeability of free space = 4π x 10⁻⁷ H/m

l is the length of the inductor, = 45 cm = 0.45 m

A is the area of the inductor (given diameter = 10 cm = 0.1 m)

$A = \pi r^2 = \frac{\pi d^2}{4} = \frac{\pi \times (0.1)^2}{4} = 0.00786 \ m^2$

$L = \frac{(1000)^2 \times (4\pi \times 10^{-7}) \times (0.00786)}{0.45} \\\\L = 0.02195 \ H\\\\L = 21.95 \ mH$

(b) The energy stored in the inductor when 21 A current ;

$E = \frac{1}{2}LI^2\\\\E = \frac{1}{2} \times (0.02195) \times (21) ^2\\\\E = 4.84 \ J$

(c) time it can be turned off if the induced emf cannot exceed 3.0 V;

$emf = L \frac{\Delta I}{\Delta t} \\\\t = \frac{LI}{emf} \\\\t = \frac{0.02195 \times 21}{3} \\\\t = 0.154 \ s$

3 0

2 years ago

What refers to a soils ability to transmit water

Keith_Richards [23]

Answer:

Permeability is also called as hydraulic conductivity, which refers to the ability of a soil to conduct water. ... Composition is of four basic categories: water, air, organic matter and minerals.

Explanation:

idk, i knew a bit and looked it up to make sure i was correct.

6 0

2 years ago

A ball is thrown downward with an initial speed of 7 m / s. The ball's velocity after 3 seconds is m / s. (g = -9.8m / s²)

yan [13]

Answer:

-36.4 m/s

Explanation:

final velocity= initial velocity + acceleration x time

7 + (-9.8)(3)= -36.4 m/s

5 0

3 years ago

What do each of the variables mean ? <br> F=__________ m=_________<br>a=___________<br>

wariber [46]

Answer:

F = Force (Measured in Newtons, N), m = Mass (Measured in kilograms, kg), and a = acceleration (Measured in metres per second squared, $m/s^{2}$

Explanation:

This is Newton's Second Law!

Hope this helps!

PLS mark as brainliest, hope this helps!

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2 years ago