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2 years ago

A student walks 1.0 mi west and then 1.0 mi north. afterward, how far is she from her starting point?

1 answer:

7 0

1.0 mi because as he has covered 1 the disrance of 1 m and then 1 m in north so he can go straight 1m north so the distance is actually 1m from the starting point

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Draw a circuit that contains 2 batteries, three lights in parallel and a switch that controls the whole circuit.

Naddik [55]

Draw a circuit that contains 2 batteries, three lights in parallel and a switch that controls the whole circuit.

6 0

2 years ago

In an experiment, a large number of electrons are fired at a sample of neutral hydrogen atoms and observations are made of how t

kakasveta [241]

Answer:

N = 1036 times

Explanation:

The radial probability density of the hydrogen ground state is given by:

$p(r) = \frac{4r^{2} }{a_{0} ^{3} } e^{\frac{-2r}{a_{0} } }$

$p(\frac{a_{0} }{2} ) = \frac{4(\frac{a_{0} }{2} )^{2} }{a_{0} ^{3} } e^{\frac{-2(\frac{a_{0} }{2} )}{a_{0} } }$

$p(2a_{0} ) = \frac{4(2a_{0}) ^{2} }{a_{0} ^{3} } e^{\frac{-4a_{0} }{a_{0} } }$

$N = 1300\frac{p(2a_{0}) }{p(\frac{a_{0} }{2} )}$

$N = 1300\frac{(2a_{0}) ^{2}e^{\frac{-4a_{0} }{a_{0} } } }{(\frac{a_{0} }{2} )^{2} e^{\frac{-a_{0} }{a_{0} } }}$

$N = 1300(16) e^{-3}$

N = 1035.57

N = 1036 times

6 0

3 years ago

Q1) An aeroplane covers a certain distance at a speed of 240 kmph in 5 hours.To cover the same distance in 1(2/3) hours, it must

Pepsi [2]

Answer:

D) 720 kmph

Explanation:

First, let's find what distance this aeroplane covered. Distance (d) is the product of speed and time - here, we have a speed of 240 kmph and a time of 5 hours, gives us

$d=240\cdot5=1200$ km

Using that same fact, we can set up a new equation to solve for speed (s) when we have a distance of 1200 km and a time of 1 2/3 hours. For the sake of cleanliness, I'm gonna rewrite 1 2/3 as the improper fraction 5/3:

$1200=(5/3)s$

Multiplying both sides of the equation by 3/5:

$s=(3/5)(1200)=720$ kmph

So our answer is D.

8 0

2 years ago

Consider a lawnmower of mass m which can slide across a horizontal surface with a coefficient of friction μ. In this problem the

inna [77]

Answer:

Fh = u*m*g / (cos(θ) - u*sin(θ))

Explanation:

Given:

- The mass of lawnmower = m

- The angle the handle makes with the horizontal = θ

- The force applied along the handle = Fh

- The coefficient of friction of the lawnmower with ground = u

Find:

Find the magnitude, Fh, of the force required to slide the lawnmower over the ground at constant speed by pushing the handle.

Solution:

- Construct a Free Body Diagram (FBD) for the lawnmower.

- Realize that there is horizontal force applied parallel to ground due to Fh that drives the lawnmower and a friction force that opposes this motion. We will use to Newton's law of motion to express these two forces in x-direction as follows:

F_net,x = m*a

- Since, the lawnmower is to move with constant speed then we have a = 0.

F_net,x = 0

- The forces as follows:

Fh*cos(θ) - Ff = 0

Where, Ff is the frictional force:

Fh = Ff /cos(θ)

Similarly, for vertical direction y the forces are in equilibrium. Using equilibrium equation in y direction we have:

- W - Fh*sin(θ) + Fn = 0

Where, W is the weight of the lawnmower and Fn is the contact force exerted by the ground on the lawnmower. Then we have:

Fn = W + Fh*sin(θ)

Fn = m*g + Fh*sin(θ)

The Frictional force Ff is proportional to the contact force Fn by:

Ff = u*Fn

Ff = u*(m*g + Fh*sin(θ))

Substitute this expression in the form derived for Fh and Ff:

Fh*cos(θ) = u*(m*g + Fh*sin(θ))

Fh*(cos(θ) - u*sin(θ)) = u*m*g

Fh = u*m*g / (cos(θ) - u*sin(θ))

5 0

3 years ago

Write 3 statements that support the conclusion that the properties of a sample of an element are the properties of its atoms

Serhud [2]

Answer:An atom is the smallest unit of matter that retains all of the chemical properties of an ... facts remain true even when the atoms or molecules are part of a living thing. ... A gold atom gets its properties from the tiny subatomic particles it's made up of. ... Most atoms contain all three of these types of subatomic particles—protons, ...

Explanation:

5 0

2 years ago