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3 years ago

What is the average velocity of a car that travels 30 kilometers due west in 0.50 hour

1 answer:

7 0

Divide the distance traveled (0.30 km) by the travel time (0.50 hrs) and get the speed in km/hr. The direction is due west. 60 km/hr west

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Question 9(Multiple Choice Worth 2 points)

ArbitrLikvidat [17]

Explanation:

O Protons and neutrons grouped in a specific pattern

O Protons and electrons spread around randomly

5 0

3 years ago

A 1-kilogram mass is attached to a spring whose constant is 21 N/m, and the entire system is then submerged in a liquid that imp

amm1812

Answer:

the required value is $x(t) = \frac{7}{4} e^{-3t}-\frac{3}{4} e^{-7t}$

Explanation:

Given that,

mass, m = 1kg

spring constant k = 21N/M

damping force = $-\beta\frac{dx}{dt} = \frac{-10dx}{dt}$

$\beta = 10$

By Newtons second law ,

The diffrential equation of motion with damping is given by

$m\frac{d^2x}{dt^2} = -kx-\beta\frac{dx}{dt}$

substitute the value of m =1kg, k = 21N/M, and $\beta = 10$

$1\frac{d^2x}{dt^2} = -21x=10\frac{dx}{dt}$

$\frac{d^2x}{dt^2} + 10\frac{dx}{dt} + 21x = 0$

suppose the equation of the form $x =e^m^t$ ,

and the auxilliary equation is given by

$m^2 + 10m + 21 = 0\\\\m^2 + 7m+3m+21=0\\\\m(m+7)+3(m+7)=0\\\\(m+7)(m+3)=0\\\\m=-7\\m=-3$

The general solution for the above differential equation is

$x(t) =C_1e^{-3t}+C_2e^{-7t}$

Derivate with respect to t

$x'(t)=-3C_1e^{-3t}-7C_2e^{-7t}$

(a)

since time is 0 then mass is one meter below

so x(0) = 1

Also it start from rest , that implies , velocity is 0 and time is 0

$x'(0) = 0$

substitute the initial condition

$C_1 +C_2 = 1$

$-3C_1-7C_2=0$

Solve the above equation to get C₁ and C₂

$C_1 =\frac{7}{4} and C_2 = -\frac{3}{4}$

substitute for C₁ and C₂ in general solution

$x(t) = \frac{7}{4} e^{-3t}-\frac{3}{4} e^{-7t}$

Thus the required value is $x(t) = \frac{7}{4} e^{-3t}-\frac{3}{4} e^{-7t}$

3 0

3 years ago

Read 2 more answers

Mike is cutting the grass using a human-powered lawn mower. He pushes the mower with a force of 45 n directed at an angle of 41Â

Andrej [43]

Answer:

work done will be equal to 305.05 J

Explanation:

We have given force exerted F = 45 N

Angle with the horizontal $\Theta =41^{\circ}$

Distance moved due to exerted force d = 9.1 m

Work done is equal to $W=Fcos\Theta \times d$ , here F is force $\Theta$ is angle with horizontal and d is distance moved due to force

So work done $W=45\times cos41^{\circ}\times 9.1=309.05J$

So work done will be equal to 305.05 J

7 0

3 years ago

Genetic information responsible for physical characteristics such as eye color, height, hair color, and skin color can be found

fredd [130]

Answer: Genetic information responsible for physical characteristics such as eye color, height, hair color, and skin color can be found in an organism's <u>DNA.</u>

<u>Explanation:</u>

Our genetic information is stored in DNA. DNA (Deoxyribonucleic acid) molecule is a double helix structure which carries information which used in development and growth of body and determines physical characteristics such as eye color, height, hair color and skin color.

8 0

3 years ago

A 9 volt battery produces a current of 0.2A. What is the resistance?

nekit [7.7K]

9/0.2 would be the ans

4 0

3 years ago