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belka [17]
2 years ago
8

A remote-controlled boat traveled 18 feet heading west and 24 feet heading south, totaling 42 feet over the course of 10 seconds

. Heading west, the boat traveled at an average speed of 3 feet per seconds less than its speed heading south. What was the average speed of the boat heading west? (Do not include the units in your response.)
Physics
1 answer:
Dominik [7]2 years ago
3 0

Answer:

3 ft/s

Explanation:

given,

distance in west, d₁ = 18 ft

distance in south, d₂ = 24 ft

time taken to travel 42 ft = 10 s

speed of boat in north = x ft/s

Speed of the boat when heading west = (x - 3) ft/s

Average\ speed = \dfrac{total\ distance}{total\ time}

v_{avg}= \dfrac{42}{10}

v_{avg}= 4.2\ ft/s

again using the above formula

now, total time

t = t₁ + t₂

10 = \dfrac{18}{x-3} + \dfrac{24}{x}

on simplifying

10 x² -72 x + 72 = 0

On solving the above equation we get

x = 6 ft/s

Hence, speed of boat in west direction, 6 -3 = 3 ft/s

           speed of boat in south direction = 6 ft/s

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Fynjy0 [20]
The formula for potential energy is PE=mgh
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When the balloon hits the ground, it rebounds slightly. What is the source of the energy for this rebound? A. When the balloon h
nevsk [136]

Answer:

The correct answer is c.    When the balloon hits the ground, the rubber envelope stretches, storing elastic potential energy; this elastic potential energy is converted to the gravitational potentiaL

Explanation:

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We can relate this force of Hooke with an elastic energy

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The correct answer is c

7 0
2 years ago
Determine the sign (+ or −) of the torque about the elbow caused by the biceps, τbiceps, the sign of the weight of the forearm,
Alex Ar [27]
Ans: 
1.  τbiceps = +(Positive)
2.  τforearm = -(Negative)
3.  τball = -(Negative)

Explanation:

The figure is attached down below.

1. T<span>orque about the elbow caused by the biceps, τbiceps:
Since Torque = r x F (where r and F are the vectors)
</span>Where r is the vector from elbow to the biceps.
<span>
We can see in the figure that F(biceps) is in upward direction, and by applying the right hand rule from r to F, we get the counterclockwise direction. The torque in counterclockwise direction is positive(+). Therefore, the sign would be +.

2. </span>Torque about the the weight of the forearm, τforearm:
Since Torque = r x F (where r and F are the vectors)
Where r is the vector from elbow to the forearm.

Also weight is the special kind of Force caused by the gravity.

We can see in the figure that W(forearm) is in downward direction, and by applying the right hand rule from r to F, we get the clockwise direction. The torque in clockwise direction is negative(-). Therefore, the sign would be -.

3. Torque about the the weight of the ball, τball:
Since Torque = r x F (where r and F are the vectors)
Where r is the vector from elbow to the ball.

Also weight is the special kind of Force caused by the gravity.

We can see in the figure that W(ball) is in downward direction, and by applying the right hand rule from r to F, we get the clockwise direction. The torque in clockwise direction is negative(-). Therefore, the sign would be -.

8 0
2 years ago
A 2 ft x 2 ft x 2 ft box weighs 100 pounds, and the weight is evenly distributed. What is the magnitude of the minimum horizonta
Tems11 [23]

Answer:

Explanation:

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= F x 2

This torque will try to turn the box . On the other hand the weight which is acting at CM will create a torque about the same corner . This torque will try to prevent the box to turn around the corner.

This torque of weight

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For equilibrium

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7 0
2 years ago
Read 2 more answers
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Answer:

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Explanation:

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solution

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and

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a = \frac{-150}{9.8}

a = -15.3 g

6 0
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