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Leya [2.2K]
3 years ago
14

A 20 ft ladder leans against a wall. The bottom of the ladder is 3 ft from the wall at time t=0 and slides away from the wall at

a rate of 2ft/sec. Find the velocity of the top of the ladder at time t=1.
Physics
1 answer:
stellarik [79]3 years ago
5 0

Answer: 0.516 ft/s

Explanation:

Given

Length of ladder L=20 ft

The speed at which the ladder moving away is v=2 ft/s

after 1 sec, the ladder is 5 ft away from the wall

So, the other end of the ladder is at

\Rightarrow y=\sqrt{20^2-5^2}=19.36\ ft

Also, at any instant t

\Rightarrow l^2=x^2+y^2

differentiate w.r.t.

\Rightarrow 0=2xv+2yv_y\\\\\Rightarrow v_y=-\dfrac{x}{y}\times v\\\\\Rightarrow v_y=-\dfrac{5}{19.36}\times 2=0.516\ ft/s

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For a series circuit what is the terminal voltage of a battery or power supply equal to in terms of the potential difference or
trapecia [35]

Answer: V=IR

Explanation: for a series circuit connected to a battery supply, the total emf across the circuit is given as

E = I(R + r) and by expanding, we have that E =IR + It

Where r is the internal resistance of the battery

I is the total current flowing in the circuit

R total load resistance in the circuit.

E is the total emf of the circuit.

The total emf is the sum of 2 separate voltages.

"IR" which is the terminal voltage and "Ir" which is the loss voltage.

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3 years ago
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Maslowich

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3 years ago
Which method of testing substances is a sure way to identify a chemical reaction?
Sergeu [11.5K]

Answer:

B

Explanation:

That's the answer. Hope it helped!

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2 years ago
Unlike a roller coaster, the seats in a Ferris wheel swivel so that the rider is always seated upright. An 80-ft-diameter Ferris
telo118 [61]

Answer:

a

   F_A  =425.42 \ N

b

  F_A_H  = 358.58 \ N

Explanation:

From the question we are told that

    The diameter of the Ferris wheel is  d  =  80 \ ft =  \frac{80}{3.281} =  24.383

    The  period of the Ferris wheel is  T  =  24 \ s

     The  mass of the passenger is  m_g  =  40 \ kg

The  apparent weight of the passenger at the lowest point is mathematically represented as

           F_A_L  =  F_c  + W

Where  F_c is the centripetal force on the passenger,  which is mathematically represented as

         F_c  =m *  r *  w^2

Where w is the angular velocity which is mathematically represented as

         w =  \frac{2* \pi   }{T}

substituting values

         w =  \frac{2* 3.142 }{24}

         w =  0.2618 \ rad/s

and  r  is the radius which is evaluated as r =  \frac{d}{2}

   substituting values

         r =  \frac{24.383}{2}

         r = 12.19 \ ft

So

          F_c  = 40 * 12.19* (0.2618)^2

          F_c  =  33.42 \ N

W is the weight which is mathematically represented as

           W =  40 * 9.8

           W =  392 \ N

So

         F_A    =  33.42 + 392

         F_A  =425.42 \ N

The  apparent weight of the passenger at the highest point is mathematically represented as

          F_A_H  =  W- F_c

substituting values

         F_A_H  = 392 -  33.42

         F_A_H  = 358.58 \ N

4 0
4 years ago
A 4300-N force from a car's engines produces an acceleration of 3.3 m/s2. What is the mass of the car?
sertanlavr [38]

Answer:The net force acting on the car is 3×103 Newtons

Explanation:

5 0
3 years ago
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