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Dafna1 [17]
3 years ago
8

Please I need help with these 2 questions. Thank you.

Physics
1 answer:
Lemur [1.5K]3 years ago
7 0
First one is D and Second one is B
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A truck using a rope to tow a 2230-kg car accelerates from rest to 13.0 m/s in a time of 15.0s. How strong must the rope be? μk
Leokris [45]

Answer:

The rope must have a force of 10084,21 N

Explanation

Acceleration calculation

The car acceleration is equal to the acceleration of the truck

ac: car acceleration\frac{m}{s^{2} }

at: truck acceleration\frac{m}{s^{2} })

ac = at= \frac{vf-vi}{t-ti}  equation(1)

Known information:

vi = Initial speed = 0, ti = initial time = 0

vf = Final speed = 13 \frac{m}{s}, t = final time =5 s

We replaced the known information in the equation(1):

ac = at = \frac{13-0}{15-0}

ac=ac=\frac{13}{15}  \frac{m}{s}

Dynamic analysis

The forces acting on the car are the following:

Wc: Car weight

N: normal force, road force on the car

Ff: Friction force

T: Force of tension

Car weight calculation:

Wc=mc*g

mc = Car mass = 2230kg

g = Gravity acceleration=9.8 \frac{m}{s^{2} }

Wc= 2230*9.8

Wc=21854 N

Normal force calculation:

Newton's first law

sum Fy= 0

N-W=0

N=W

N=21854 N

Friction force calculation (Ff):

We have the formula to calculate the friction force:

Ff = μk * N  Equation (3)

μk kinetic coefficient of friction

We know that μk = 0.373and N= 21854N ,then:

Ff=0.373*21854

Ff=8151.54 N

Calculation of the tension force in the rope (T):

Newton's Second law

sum Fx= mc*ac

T-Ff=mc*ac

T=2230(\frac{13}{15}) + 8151.54

T=10084,21 N

Answer: The rope must have a force of 10084,21 N

8 0
3 years ago
26. An ice-skater who weighs 200 N is gliding across the ice. If the force of friction is 4 N. what is the
Scrat [10]

Answer:

0.02

Explanation:

coefficient of kinetic friction = μ

force of friction = Ff

Normal Force = FN, but

FN = -W

Ff = -μFN

so μ = Ff/FN

= 4N/200N

= 0.02.

7 0
3 years ago
Which statement is true about the theory of plate tectonics and the theory of continental drift?
NISA [10]

Answer:

The theory of plate tectonics explains how continental movements could occur. B. The theory of plate tectonics shows that continental movements could not have happened. C. The theory of plate tectonics tells us exactly where the continents were before Pangaea divided. D. The theory of plate tectonics shows that Pangaea was impossible, but .

Explanation:

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3 years ago
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Natalija [7]
<span>the one that should be taken as consideration when describing the quality of a sound is: D.The number of the overtones in the sound Too many overtones indicated that there is too many unrelated sound that make a lot of the sound's part became redundant and unecessary</span>
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3 years ago
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Can you answer my questions. Please help me ​
earnstyle [38]

Answer:

answered it.................

8 0
3 years ago
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