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pickupchik [31]
3 years ago
15

A car, moving along a straight stretch of highway,

Physics
1 answer:
yarga [219]3 years ago
5 0
<span>We know that an object in moving with acceleration follow the rule according that the distance covered will be : d = Vi*t + 1/2*a*t^2 where d is distance, Vi is initial speed, and a is acceleration Then after 1 km which is 1000 metres we have: 1000 = Vi *71.2 + 1/2*0.0499*(71.2)^2 Vi = (1000-1/2*0.0499*(71.2)^2)/71.2 = 1000/71.2 - 1/2*0.0499*71.2 = 12.27 m/s Then the car was going at 12.27 m/s when started to accelerate.</span>
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Explain why it took so long for psychology to be recognized and what things helped it to get recognized.
Juli2301 [7.4K]
It took so long because at the time there was no way for people to study the behavior formally. im not sure what helped it get recognized but i know wihelm wundt helped get it recongnized. 

sorry i couldnt be much help
4 0
3 years ago
A proton and an electron are released from rest, with only the electrostatic force acting. Which of the following statements mus
lbvjy [14]

Answer:

their electrical potential energy decreases. True, because of the negative sign as the distance decreases, it becomes more negative.

The kinetic energy increases. True, the force is attractive as the distance decreases the force increases, so acceleration and therefore the speed

Explanation:

The only force between the proton and the electron is electric

      Fe = k q1q2 / r2

      Fe = - k e2 / r2

We can see that it is an attractive force (negative sign)

The electric power energy is

       U = k q1 q2 / r

       U = -k e2 / r

 

The kinetic energy is

       K = ½ m v2

With the expressions for each term we can analyze the sentences :

Their electric potential energy increases. False,

their electrical potential energy decreases. True, because of the negative sign as the distance decreases, it becomes more negative.

The kinetic energy increases. True, the force is attractive as the distance decreases the force increases, so acceleration and therefore the speed

Kinetic energy decreases False

The acceleration decreases.  False, as the force increases so does the acceleration

7 0
3 years ago
In a race, Usain Bolt accelerates at
jeka94

Answer:

65.87 s

Explanation:

For the first time,

Applying

v² = u²+2as.............. Equation 1

Where v = final velocity, u = initial velocity, a = acceleration, s = distance

From the question,

Given:  u = 0 m/s (from rest), a = 1.99 m/s², s = 60 m

Substitute these values into equation 1

v² = 0²+2(1.99)(60)

v² = 238.8

v = √238.8

v = 15.45 m/s

Therefore, time taken for the first 60 m is

t = (v-u)/a............ Equation 2

t = (15.45-0)/1.99

t = 7.77 s

For the final 40 meter,

t = (v-u)/a

Given: v = 0 m/s(decelerates), u = 15.45 m/s, a = -0.266 m/s²

Substitute into the equation above

t = (0-15.45)/-0.266

t = 58.1 seconds

Hence total time taken to cover the distance

T = 7.77+58.1

T = 65.87 s

3 0
3 years ago
What is a concern about recovered memories?
Fittoniya [83]

Answer:

D because those are both concerning.

4 0
3 years ago
Read 2 more answers
A fish finder uses a sonar device that sends 20,000-Hz sound pulses downward from the bottom of the boat, and then detects echoe
mrs_skeptik [129]

Answer:  The minimum time between pulses (in fresh water)

= 0.3106 s

Explanation:

To calculate the speed of echoes sounds, we will use

Speed = 2x/t

Where x = distance and t = total time.

Please note that:

sound travels at 343 m/s in air. But it travels at 1,481 m/s in water (almost 4.3 times as fast as in air); 

Total distance = 2 × 230 = 460m

Using speed of sound in water

1481 = 460/t

t = 460/1481

t = 0.3106

3 0
2 years ago
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