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uysha [10]
3 years ago
6

a) Calculate the magnitude of displacement of the car in 40 seconds. b) During which part of the journey was the car acceleratin

g? c) Calculate the magnitude of average velocity of the car.

Physics
1 answer:
Zielflug [23.3K]3 years ago
7 0

Answer:

a)  600 meters

b) between 0 and 10 seconds, and between 30 and 40 seconds.

c) the average of the magnitude of the velocity function is 15 m/s

Explanation:

a) In order to find the magnitude of the car's displacement in 40 seconds,we need to find the area under the curve (integral of the depicted velocity function) between 0 and 40 seconds. Since the area is that of a trapezoid, we can calculate it directly from geometry:

Area \,\,Trapezoid=(\left[B+b]\,(H/2)\\displacement= \left[(40-0)+(30-10)\right] \,(20/2)=600\,\,m

b) The car is accelerating when the velocity is changing, so we see that the velocity is changing (increasing) between 0 and 10 seconds, and we also see the velocity decreasing between 30 and 40 seconds.

Notice that between 10 and 30 seconds the velocity is constant (doesn't change)  of magnitude 20 m/s, so in this section of the trip there is NO acceleration.

c) To calculate the average of a function that is changing over time, we do it through calculus, using the formula for average of a function:

Average\,of\,f(x)=\frac{1}{b-a} \int\limits^b_a {f(x)} \, dx

Notice that the limits of integration for our case are 0 and 40 seconds, and that we have already calculated the area under the velocity function (the integral) in step a), so the average velocity becomes:

Avearage=\frac{600\,\,m}{40\,\,s}= 15\,\,\frac{m}s}

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Answer:

Explanation:

Given

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0-(V)^2=2\times (-g)\cdot H

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i.e. maximum height is dependent on square of initial velocity

for twice the height

2H=\frac{(V')^2}{2g}

on comparing

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A ball is rolled at a velocity of 25 m/sec. after 13.5 seconds, it comes to a stop . What is the acceleration of the ball?
nexus9112 [7]

Answer:

The answer to your question is a = -1.85 m/s² the acceleration is negative because it is coming to stop.

Explanation:

Data

vo = 25 m/s

t = 13.5 s

a= ?

vf = 0 m/s

Formula

vf = vo + at

solve for a

a = (vf - vo)/t

Substitution

a = (0 - 25) / 13.5

Simplification

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Result

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A girl stands on the edge of a merry-go-round of radius 1.71 m. If the merry go round uniformly accerlerates from rest to 20 rpm
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Answer:

a = 0.53 m/s^2

Explanation:

initially the merry go round is at rest

after 6.73 s the merry go round will accelerates to 20 rpm

so final angular speed is given as

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