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Masja [62]
2 years ago
9

Sandy is on a road trip. She leaves at 8:00 AM. It takes her 2 hours to drive 200 kilometers. She stops at a rest stop for half

an hour. Then, she drives for 100 more kilometers, which takes her an hour and a half. What is Sandy's average velocity?
Physics
1 answer:
lutik1710 [3]2 years ago
0 0
The average velocity of Sandy is given by the total distance covered S divided by the total time taken t:
v= \frac{S}{t}

The total distance covered is
S=200 km+0+100 km=300 km
while the total time taken is 2 hours + half an hour (for the rest) + 1 hour and half, so
t=2h+0.5h+1.5 h=4 h
Therefore, the average velocity is 
v= \frac{S}{t}= \frac{300 km}{4 h}=75 km/h
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Juli2301 [7.4K]

Answer:

0.0984

Explanation:

From the first diagram attached below; a free flow diagram shows the interpretation of this question which will be used  to solve this question.

From the diagram, the horizontal component of the force is:

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Replacing 42°  for θ and 87.0° for F

F_X =87.0 \ N \ *cos \ 42 ^\circ

F_X =64.65 \ N

On the other hand, the vertical component  is ;

F_Y = Fsin \ \theta

Replacing 42°  for θ and 87.0° for F

F_Y =87.0 \ N \ *sin \ 42 ^\circ

F_Y =58.21  \ N

However, resolving the vector, let A be the be the component of the mutually perpendicular directions.

The magnitude of the two components is shown in the second attached diagram below and is now be written as A cos θ and A sin θ

The expression for the frictional force is expressed as follows:

f = \mu \ N

Where;

\mu is said to be the coefficient of the friction

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Replacing F_Y \ for \ F_{sin \  \theta}. The normal reaction can now be:

N = mg \ - \ F_Y

By balancing the forces, the horizontal component of the force equals to frictional force.

The horizontal component of the force is given as follows:

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Making \mu the subject of the formular in the above equation; we have the following:

\mu \ = \ \frac{F_X}{mg - F_Y}

Replacing the following values: i.e

F_X \ = \ 64.65 \  N

m = 73 Kh

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F_Y = \ 58.21 N

Then:

\mu \ = \ \frac{64.65 N}{(73.0 kg)(9.8m/s^2) - (58.21 \ N)}

\mu = 0.0984

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2 years ago
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nirvana33 [79]

Answer:

Work done, W = 19.6 J

Explanation:

It is given that,

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Distance covered by the block, d = 2 m

As the block passes through the rough part, some of the energy gets lost and this energy is equal to the work done by the kinetic energy.

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Answer:

45.8 cm

Explanation:

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x = 0.5 * (√(35) - 5) meters

x = 0.5 * (5.916 - 5)

x = 0.5 * (0.916)

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an airplane releases a ball as it flies parallel to the ground at a height of 235m. if the ball lands on the ground exactly at 2
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The circuit in Fig. P4.23 utilizes three identical diodes having IS = 10−14 A. Find the value of the current I required to obtai
Sliva [168]

Answer:

v = \frac{2 V}{3}= 0.667 v

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Since we know that 1 mA is drawn away from the output then the real value for I would be

I_D = I = 3.86 mA -1 mA= 2.86 mA

And for this case the value for v_D would be:

V_D = V_T ln (\frac{I_D}{I_T})= 0.025 ln (\frac{0.0029}{10^{-14}})= 0.660 V

And the output votage on this case would be:

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And the net change in the output voltage would be:

\Delta V = |2 v-1.98 V| = |0.02 V |= 20 m V

Explanation:

For this case we have the figure attached illustrating the problem

We know that the equation for the current in a diode id given by:

I_D = I_s [e^{\frac{V_D}{V_T}} -1] \approx I_S e^{\frac{V_D}{V_T}}

For this case the voltage across the 3 diode in series needs to be 2 V, and we can find the voltage on each diode v_1 + v_2 + v_3= 2 and each voltage is the same v for each diode, so then:

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I_D =I= I_S e^{\frac{V_D}{V_T}}

And replacing we have:

I = 10^{-14} A e^{\frac{0.667}{0.025}}= 3.86x10^{-3} A = 3.86 mA

Since we know that 1 mA is drawn away from the output then the real value for I would be

I_D = I = 3.86 mA -1 mA= 2.86 mA

And for this case the value for v_D would be:

V_D = V_T ln (\frac{I_D}{I_T})= 0.025 ln (\frac{0.0029}{10^{-14}})= 0.660 V

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V = 3 V_D = 3 *0.660 V = 1.98 V

And the net change in the output voltage would be:

\Delta V = |2 v-1.98 V| = |0.02 V |= 20 m V

5 0
2 years ago
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