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3 years ago

The graph below shows the velocity of a car as it attempts to set a speed record. At what point is the car the fastest?

Physics

1 answer:

Maksim231197 [3]3 years ago

6 0

Answer:

B). 3.4 s

Explanation:

As we can see the graph is given between velocity and time

so here we can see that the velocity is changing here with time and initially for some time it moves with constant speed

Then it's speed decreases to next few second and then speed increases to its maximum value

The time after which velocity comes to its maximum value will reach after t = 3 s

so out of the all given options most correct option will be

$t = 3.4 s$

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Which of these statements best represents the law of conservation of energy

Shkiper50 [21]

Energy cannot be created or destroyed. This statement is known as law of conservation of energy, and it implies that whenever a certain form of energy does change, the loss of this form of energy must have converted into an another type of energy. A typical example is an object falling to the ground: initially, the object has gravitational potential energy. As the object falls down, it loses potential energy (since its altitude from the ground decreases), but it acquires kinetic energy (because its velocity increases). In this example, potential energy has converted into kinetic energy, but the total energy of the object has remained constant.

5 0

3 years ago

A skier approaches the base of an icy hill with a speed of 12.5 m/s. The hill slopes upward at 24° above the horizontal. Ignorin

jonny [76]

when object is placed on inclined plane then we will have net force along the inclined plane which is due to the component of weight along the incline

so we can say that

$F_x = W sin\theta$

$F_x = mgsin24$

now in order to find the acceleration we can use Newton's II law

$F_{net} = ma$

$mgsin24 = ma$

$a = g sin24$

$a = 4 m/s^2$

and the direction is along the inclined plane downwards as weight always pull downwards

So correct answer will be

<em>B)4.0m/s2, directed down the slope</em>

7 0

3 years ago

A spacecraft heading for Pluto will take pictures of several other planets on its way. The above equation gives the distance, dd

ioda

Answer:

The maximum number of days for the trip

Explanation:

Given

$d = 1.06(212 - t)$ --- Missing Equation

Required

What does d represent?

From the question, we understand that t represent the number of days;

So, by default 212 represent days

Going further:

For the equation, $d = 1.06(212 - t)$ to be valid; the value of t must be within the interval;

$0 \le t \le 212$

When $t = 0;$

that is the beginning of the journey

As t increases;

212 - t decreases

Until the point where t = 212,

This signifies the end of the journey

So: 212 - t indicates a particular day between 0 and 212.

Hence, 212 represents the maximum number of days for the trip.

5 0

3 years ago

A biologist looking through a microscope sees a bacterium at r⃗ 1=2.2i^+3.7j^−1.2k^μm(1μm=10−6m). After 6.2 s , it's at r⃗ 2=4.6

stiv31 [10]

The Average velocity for the bacterium is 0.75 unit/sec.

<u>Explanation:</u>

The given values are in the vector form

Where,

dS = distance covered

dT = time interval

Now, to calculate distance covered, we have

$|d S|=\sqrt{d S^{2}}$

$d S=r_{2}-r_{1}$

d S=(4.6 i+1.9 k)-(2.2 i+3.7 j - 1.2 k)

d S=(4.6-2.2) i+(0-3.7) j+(1.9+1.2) k

d S=2.4 i-3.7 j+3.1 k

Now, putting these values in the standard formula to evaluate the average velocity, we get;

$v_{a v g}=\frac{|\mathrm{d} S|}{d T}$

$v(a v g)=\frac{|\sqrt{\left\{\left(2.4^{2}\right)+\left(3.7^{2}\right)+\left(3.1^{2}\right)\right\}}|}{7.2}$

As dT=7.2 sec

Now,

Solving the equation, we get;

$v(a v g)=\frac{5.390732789}{7.2}$

$\begin{aligned}&v(a v g)=\frac{5.39}{7.2}\\&v(a v g)=0.748611111\\&v(a v g)=0.75 \text { units / sec }\end{aligned}$

Hence, the average velocity for the bacterium is 0.75 unit/sec.

3 0

3 years ago

A hydraulic jack has a small piston area A1 = 2 m^2 and the large piston area A2 = 20 m^2. A 1500 Kg car needs to be lifted. a)

Alex777 [14]

Answer:

1471.5 Newton

Explanation:

Small piston area = A₁ = 2 m²

Large piston area A₂ = 20 m

m = Mass of car = 1500 kg

g = Acceleration due to gravity = 9.81 m/s²

Force

F = mg = 1500×9.81 = 14715 N

Force applied by car is 14715 N

a) Pascal's law

$\frac{F_1}{A_1}=\frac{F_2}{A_2}\\\Rightarrow F_1=F_2\frac{A_1}{A_2}\\\Rightarrow F_1=14715\frac{2}{20}=1471.5$

Force required is 1471.5 Newton

b) Mechanical advantage

$\frac{F_2}{F_1}=\frac{14715}{1471.5}=10$

Mechanical advantage is 10

5 0

3 years ago