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4 years ago

Someone help please I am suffering from these

Physics

1 answer:

seropon [69]4 years ago

3 0

i will b i don't now but you said you was suffering so i have to help you i'm going to put a thank you on you name okay bye

You might be interested in

A girl standing upright exerts a pressure of 15000 N/m2 on the floor. Given that the total area of contact of shoes and the floo

lapo4ka [179]

Explanation:

F=15000/0.02

=300N

total area contact of the shoes and floor when stood in one foot=0.02m^2/2=0.01m^2

P=F/A

=300/0.01

=30 000Pa/30 000Nm^-2

in another way=15000×2

=30000N/m^2

5 0

4 years ago

As much as 90% of the matter in the universe may be unseen “dark matter.” where is this dark matter?

lyudmila [28]

As much as 90% of the matter in the universe my be unseen i.e. dark matter. There is a variety of explanations offered by many astronomers and physicists for this dark matter. It could merely be ordinary material such as ultra-faint stars, cold gas, large or small black holes or dust scattered around the universe, all of which emit or reflect too little radiation for our instruments to detect. It could also consist of exotic, unfamiliar particles that we have not figured out how to observe.

7 0

3 years ago

A freight car of mass M contains a mass of sand m. At t = 0 a constant horizontal force F is applied in the direction of rolling

Veronika [31]

Answer:

Amount of linear movement

Explanation:

Our system is defined by the rate of change in mass that

leaves the car $\Delta m_ {s}$ , this happens during a time interval

$[t, t + \Delta t]$ , in addition to freight car and sand at time t.

In this way we need to define the two states:

State 1,

consider $t, m_ {c} (t) + \Delta m_ {s}$ and V.

State 2,

consider $t + \Delta t, m_ {c} (t), V + V \Delta V$

In this state is the mass of sand output, which

is composed of

$\Delta m_{s}, V + \Delta V$

In this way we define the Linear movement in x, like this:

$p_ {x} (t) = (\Delta m_ {s} + m_ {c} (t)) v$

$p_ {x} (t+\Delta t) = (\Delta m_ {s} + m_ {c} (t)) (v + \Delta v)$

$m_ {c} (t) = m_ {c, 0} - bt = m_ {c} + m_ {s} -bt$

In this way we proceed to obtain the Force

$F =\lim_{\Delta t \rightarrow 0} \frac {p_x (t + \Delta t) -p_ {x} (t)} {\Delta t}$

$F = lim_{\Delta t \rightarrow 0} m_ {c} (t) \frac {\Delta v} {\Delta t} + lim_{\Delta t \rightarrow 0} m_ {s} (t) \frac {\Delta v} {\Delta T}$

Since the mass of the second term becomes 0, the same term is eliminated, thus,

$F = m_ {c} (t) \frac {dv} {dt}$

$\int\limit ^ {v (t)} _ {v = 0} dv = \int\limit^t_0 \frac{Fdt} {m_ {c} + m_ {s} -bt}$

$V (t) = - \frac {F} {b} ln (\frac {m_c + m_s-bt} {m_c + m_s})$

3 0

4 years ago

A train is moving with a velocity of 70 km/h.

hodyreva [135]

Answer:

B: It is moving north.

Explanation:

We are told that a train is moving with a velocity of 70 km/h.

Now, we are also told that the positive direction is north.

This means that the train is moving in the northern direction.

We can't say if it is speeding up or not because we are not given the acceleration.

Thus, option B is correct

6 0

3 years ago

A Porsche challenges a Honda to a 400 m race. Because the Porsche’s acceleration is 3.50 m/s2 is larger than the Honda’s 3.00 m/

Talja [164]

Answer:

There are a couple of ways to do this.

(i) Set up the two kinematics equations:

Honda: s = ½at² = ½ * 3m/s² * t² = 1.5m/s² * t²

Porsche: S = ½ * 3.5m/s² * (t - 1s)² = 1.75m/s² * (t - 1s)²

When does s = S ? Dropping units for ease,

1.5t² = 1.75(t-1)²

which is quadratic and has solutions at t = 0.5 s → which is no good, since it would leave the porsche with -0.5 s, which isn't possible, and

t = 13.5 s

When they've gone the same distance, they've gone

d = 1.5m/s² * (13.5s)² = 273 meters

The Porsche wins easily. ◄

Want to make it interesting? Give the Honda 1¼ seconds.

Then t = 16.85 s

and x = 1.5m/s² * (16.85s)² = 426 m

and the Honda squeaks out a victory.

You could also just find the time it takes each to go 400 m:

Honda: t = √(2s/a) = √(800m / 3.0m/s²) = 16.3 s

Porsche: T = √(800m / 3.5m/s²) = 15.1 s

Since the Porsche only gives up 1 s at the beginning, it wins by 0.2 s.

Explanation:

6 0

3 years ago