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3 years ago

I'm new to brainy, but here is my question.

Physics

2 answers:

skad [1K]3 years ago

8 0

680 is the right answer

Fittoniya [83]3 years ago

7 0

Answer: 680 J

Explanation:

Andre's mechanical energy is given by:

$E=K+U$

where

K is the kinetic energy

U is the gravitational potential energy

The kinetic energy in this case is zero, because Andre is sitting, so its speed is zero: v=0, and the kinetic energy is

$K=\frac{1}{2}mv^2=\frac{1}{2}(77.1 kg)(0)^2=0$

The gravitational potential energy is instead

$U=mgh=(77.1 kg)(9.8 m/s^2)(0.90 m)=680.0 J$

So, the total mechanical energy is

$E=U=680.0 J$

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A pilot heads his jet due east. The jet has a speed of 475 mi/h relative to the air. The wind is blowing due north with a speed

oksian1 [2.3K]

Explanation:

a. The velocity of the wind as a vector in component form will be represented as v vector:

$v=30j$

b.The velocity of the jet relative to the air as a vector in component form will be represented as u vector

$u=475i$

c. The true velocity of the jet as a vector will be represented as w:

$w=u+v$

$w=475i+30j$

d. The true speed of the jet will be calculated as:

$IwI=\sqrt{(475)^2+(30)^2}$

$IwI=\sqrt{225625+900}$

$IwI=\sqrt{226525}$

$IwI=476 mi/h$

e. The direction of the jet will be:

$tita=tan^{-1}\frac{30}{475}$

$tita=tan^{-1}(0.0632)$

$tita=3.62degrees,or,N86.38degreesS$

7 0

3 years ago

Resistors 1 and 2− R1 = 50 Ω , R2 = 90 Ω − are connected in series to a 6.0-V battery. Part APart complete What is the potential

kondor19780726 [428]

Answer:

Part A: The voltage across resistor R1 is approximately $\rm 2.1 \; V$ .

Part B: When the value of resistor R1 decreases, the current in this circuit will increase.

Part C: When the value of resistor R1 decreases, the voltage across resistor R1 will decrease.

Explanation:

Resistor R1 and and R2 are connected in series. That's equivalent to a single resistor of $R_1 + R_2 = 50 + 90 = 140\; \Omega$ . The voltage across the two resistor, combined, is equal to $\rm 6\; V$ . Hence by Ohm's Law, the current through the circuit will be equal to $\rm \dfrac{6\; V}{140\; \Omega} = \dfrac{3}{70}\; A$ .

These two resistors are connected in series. The voltage across each of them might differ. However, the current through each of them should both be equal to the current through the circuit. In this case, the current through both R1 and R2 should be equal to $\rm \dfrac{3}{70}\; A$ . Apply Ohm's Law (again) to find the voltage across R1:

$V = I \cdot R = \dfrac{3}{70} \times 50 \approx \rm 2.1\; V$ .

Since the equivalent resistance is equal to $R_1 + R_2$ , when the value of $R_1$ decreases, the equivalent resistance will also decrease. By Ohm's Law, $I = \dfrac{V}{R}$ . When the value of the denominator ( decreases, the value of the quotient, $I$ the current through the circuit, will increase.

Keep in mind that if two resistors are connected in series,

$I(R_1) = I(\text{Circuit}) = I(R_2)$ .

The resistance of R1 decreases, while the current through it increases. Applying Ohm's Law on R1 won't give much useful information. However, since the resistance of R2 stays the same, the voltage across it will increase when its current increases (again by Ohm's Law.)

Again, since the two resistors are connected in series,

$V(R_1) + V(R_2) = V(\text{Circuit}) = \rm 6 \; V$ ,

when the voltage across R2 increases, the voltage across R1 will decrease.

4 0

3 years ago

Please help... I'm confused on what I represents in terms of solving the total current. Would variable would I be singling out?

pentagon [3]

Answer:

the researcher say hi for us the best pa the best of us are going out to eat that I can get my money toward a little bit but the best of luck to be at work by then and we will see what the status

7 0

3 years ago

Is this right

erik [133]

Everything with 1 symbol = Element
Everything with multiple symbols = Compound

Elements are the smallest particles (if we go further things start to get weird). Compounds are ALWAYS made up from elements.

6 0

4 years ago

Suppose a car's standard tires are replaced with tires 1.30 times larger in diameter.(i) Will the car's speedometer reading be (

Nezavi [6.7K]

The answer is 1.30 times too low.

<h3>What is a speedometer reading?</h3>

According to the law, speedometers can never understate a vehicle's speed while never exceeding 110% of the real speed + 6.25 mph. Therefore, if you're traveling at 40 mph, your speedometer may display up to 50.25 mph, but it will never show a speed below 40 mph.
While the speedometer displays how fast your car is moving, the odometer displays how far it has traveled. According to Tetzlaff, the speedometer's accuracy in most cars, including Volkswagens, is typically within a few percentage points of actual speed.
A car's speedometer is a tool that displays the vehicle's speed. An odometer is yet another accessory connected to a speedometer. The car's odometer displays the distance driven. The speedometer, as we all know, displays the pace of every single moment.
Federal law prohibits speedometers from having an inaccuracy of more than 5% (usually stated as plus/minus 2.5% relative to the real speed), according to Dan Edmunds, an automotive engineer and director of vehicle testing at Edmunds.com.

The answer is 1.30 times too low.

To learn more about speedometers, refer to:

brainly.com/question/3397467

#SPJ4

5 0

2 years ago