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3 years ago

Can someone help with numbers 5-8??

Physics

1 answer:

Keith_Richards [23]3 years ago

7 0

5. Left

Explanation: centripetal acceleration is the acceleration that acts on an object which is moving by circular motion. The direction of the centripetal acceleration is always towards the centre of the circular trajectory: that means that for a car following a bend, the direction of the centripetal acceleration is towards the centre of the bend, and so it is towards the left if the bend is towards the left, and towards the right if the bend is towards the right.

In this example, the road in this bend is going to the left, so centripetal acceleration is toward the left as well.

6. Greater

Explanation: Inertia represents the tendency of an object at staying in motion if it is moving, and at staying at rest if the object is at rest. We can also see inertia as a measure of "how difficult it is" to put an object in motion. Due to this definition, we can also notice that inertia is directly proportional to the mass of the object: the greater the mass, the greater the inertia, because it is more difficult to put the object in motion.

So, in this example, the greater the boulder's mass, the greater inertia it has.

7. Direction

Explanation: displacement is a vector quantity that represents the difference in position between an object and a starting point. Because it is a vector, displacement consists of two elements:

- A magnitude, which is equal to the object's distance from the starting point

- A direction, again compared to the starting point

So, displacement depends on the object's distance and direction from the starting point.

8. Negative

Explanation: acceleration is defined as the rate of change of velocity; in formula:

$a=\frac{v-u}{t}$

where v is the final velocity, u the initial velocity, and t the time taken to accelerate from u to v. From the formula, we see that:

- When the final velocity (v) is greater than the initial velocity (u), acceleration is positive

- When the final velocity (v) is smaller than the initial velocity (u), acceleration is negative

In this problem, we have a car slowing down: it means that the final velocity is smaller than the initial velocity, so in this case acceleration is negative.

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In a series circuit the total current is the same throughout resistors and so:

$I_{total}=I_1=I_2$

The voltage is distributed throughout the resistors and so:

$V_{total}=V_1+V_2$

and the total resistance can be calculated by adding up the resistors resistance:

$R_{total}=R_1+R_2$

First thing is to calculate the total resistance and so:

$R_{total}=6\Omega + 4\Omega = 10\Omega$

And by Omh's law V=IR we have:

$V_{total}=I_{total}R_{total}\\\\I_{total}=\frac{V_{total}}{R_{total}}= \frac{12V}{10\Omega} =1.2A$

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3 years ago

Read 2 more answers

Suppose a certain car supplies a constant deceleration of A meter per second per second. If it is traveling at 90km/hr. When. th

aksik [14]

Answer:

i)-6.25m/s

ii)18 metres

iii)26.5 m/s or 95.4 km/hr

Explanation:

Firstly convert 90km/hr to m/s

90 × 1000/3600 = 25m/s

(i) Apply v^2 = u^2 + 2As...where v(0m/s) is the final speed and u(25m/s) is initial speed and also s is the distance moved through(50 metres)

0 = (25)^2 + 2A(50)

0 = 625 + 100A....then moved the other value to one

-625 = 100A

Hence A = -6.25m/s^2(where the negative just tells us that its deceleration)

(ii) Firstly convert 54km/hr to m/s

In which this is 54 × 1000/3600 = 15m/s

then apply the same formula as that in (i)

0 = (15)^2 + 2(-6.25)s

-225 = -12.5s

Hence the stopping distance = 18metres

(iii) Apply the same formula and always remember that the deceleration values is the same throughout this question

0 = u^2 + 2(-6.25)(56)

u^2 = 700

Hence the speed that the car was travelling at is the,square root of 700 = 26.5m/s

In km/hr....26.5 × 3600/1000 = 95.4 km/hr

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3 years ago

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Anna71 [15]

Answer:

35 mph

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The key of this problem lies in understanding the way that projectile motion works as we are told to neglect the height of the javelin thrower and wind resistance.

When the javelin is thown, its velocity will have two components: a x component and a y component. The only acceleration that will interact with the javelin after it was thown will be the gravety, which has a -y direction. This means that the x component of the velocity will remain constant, and only the y component will be affected, and can be described with the constant acceleration motion properties.

When an object that moves in constant acceleration motion, the time neccesary for it to desaccelerate from a velocity v to 0, will be the same to accelerate the object from 0 to v. And the distance that the object will travel in both desaceleration and acceleration will be exactly the same.

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what is the power of an electrical device which operates with a current of 12.4 A and a potential difference of 12 V

jek_recluse [69]

148.8 Watts

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P = VI

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= 148.8 Watts

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