Which three elements have strong magnetic properties?

A satellite orbits earth at 800 m from the earth's center. Gravity at this location is 6.2 m/s^2. What is the velocity of the sa

oksano4ka [1.4K]

Recall that the magnitude of the acceleration $a$ of a particle moving with speed $v$ in a circular path around a point at a distance $R$ away from the particle is given by

$a=\dfrac{v^2}R$

So, the satellite has velocity

$6.2\,\dfrac{\rm m}{\mathrm s^2}=\dfrac{v^2}{800\,\rm m}\implies v=70.4\,\dfrac{\rm m}{\rm s}$

pointing in the direction tangent to the circular path.

6 0

3 years ago

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lys-0071 [83]

Answer:

The object will have an upward acceleration

Explanation:

Let's consider the forces applied on the box. We have only two forces:

- The applied force of push, $F_p$ , downward

- The force of gravity, $W$ , (also known as weight of the object), downward

Therefore, the net force on the box is:

$F_{net}=F_p -W$

Here, we know that force applied is equal or greater than the weight, so

$F_p \geq W$

And therefore the net force is greater than zero:

$F_{net}\geq 0$ (1)

According to Newton's second law of motion, the net force on the box is equal to the product between its mass and its acceleration:

$F_{net}=ma$

where

m is the mass of the box

a is its acceleration

Given (1), this means that

$a\geq 0$

Therefore, the box will have an upward acceleration.

In this case force example we have:

$F_p = 100 N\\W = 40 N$

So the mass of the box is

$m=\frac{W}{g}=\frac{40}{10}=4 kg$

So the net force is

$F_{net}=F_p-W=100-40=60 N$

And the acceleration is

$a=\frac{F_{net}}{m}=\frac{60}{4}=15 m/s^2$

4 0

3 years ago

A student connects a 1 hp motor to a bicycle. How much time will it take for the bicycle to accelerate from rest to a speed of 5

bija089 [108]

Answer:

t=2s

Explanation:

The definition of power is:

$P=\frac{W}{t}$

And the work-energy theorem states that:

$W=\Delta K$

Since the movement starts from rest, we have that:

$\Delta K=\frac{mv_f^2}{2}-\frac{mv_0^2}{2}=\frac{mv_f^2}{2}$

And putting all together:

$P=\frac{mv_f^2}{2t}$

Since we want the time taken:

$t=\frac{mv_f^2}{2P}$

Which for our values is:

$t=\frac{(120kg)(5m/s)^2}{2(746W)}=2s$

7 0

3 years ago

Read 2 more answers

_____ friction is the force that sliding objects experience

Gnesinka [82]

Answer:

Sliding friction is the force that sliding objects experience

Explanation:

7 0

3 years ago

A world-class sprinter running a 100 m dash was clocked at 5.4 m/s 1.0 s after starting running and at 9.8 m/s 1.5 s later. In w

cupoosta [38]

Answer:

<em>The output power is greater in the interval from 1.0 s to 2.5 s</em>

Explanation:

<u>Physical Power </u>

It measures the amount of work W an object does in certain time t. The formula needed to compute power is

$\displaystyle P=\frac{W}{t}$

Work can be computed in several ways since we are given the motion conditions, we'll use this formula, for F= applied force, x=distance parallel to F

$W=F.x$

The second Newton's law gives us the net force as

$F=m.a$

being m the mass of the object and a the acceleration it has for a given period of time. In our problem, we have two different behaviors for each interval and we must calculate this force since the acceleration is changing. Let's calculate the acceleration in the first interval. We can use the formula for the final speed vf knowing the initial speed vo (which is 0 because the sprinter starts from rest), the acceleration a, and the time t:

$v_f=v_o+at$