When you see yourself in a plane mirror, the image is always:

If your brakes fail, look for something to rub against, try to pick something that will not give way.True or False?

Yanka [14]

Answer:

False

Explanation:

False

If brakes fail then we should not run against any object or wall to slow down the speed instead we should use friction forces slow down the car and shift gear to neutral to cease any acceleration.

By driving zig-zag motion friction force on the tires may stop the car after some distance.

Do not try to shut off the engine as it will lock the steering mechanism any prove fatal.

7 0

3 years ago

A horseshoe magnet is moved toward a pile of iron shavings. The iron shavings divide and attach to both ends of the magnet. How

Aliun [14]

Answer:

Kinetic energy increases because iron shavings move in the direction of magnetic force.

Potential energy decreases, and kinetic and thermal energy increase.

Potential energy increases because movement is in the opposite direction of the magnetic field.

They seek a rail line not affected by friction.

5 0

3 years ago

You attach a 3.10 kg weight to a horizontal spring that is fixed at one end. You pull the weight until the spring is stretched b

dolphi86 [110]

Answer:

0.785 m/s

Explanation:

Hi!

To solve this problem we will use the equation of motion of the harmonic oscillator, i.e.

$x(t) = A cos(\omega t )+B sin(\omega t)$ - (1)

$\frac{dx}{dt}(t) = \omega (B cos(\omega t )- A sin(\omega t)$ - (1)

The problem say us that the spring is released from rest when the spring is stretched by 0.100 m, this condition is given as:

$x(0) = 0.100$

$\frac{dx}{dt}(0) = 0$

Since cos(0)=1 and sin(0) = 0:

$x(0)=A$

$\frac{dx}{dt}(0) = -B\omega$

We get

$A =0.100\\B = 0$

Now it say that after 0.4s the weigth reaches zero speed. This will happen when the sping shrinks by 0.100. This condition is written as:

$x(0.4) = - 0.100$

Since

$x(t) = 0.100 cos(\omega t)\\ -0.100=x(0.4)=0.100cos(\omega 0.4)$

This is the same as:

$-1 = cos(0.4\omega)$

We know that cosine equals to -1 when its argument is equal to:

(2n+1)π

With n an integer

The first time should happen when n=0

Therefore:

π = 0.4ω

or

ω = π/0.4 -- (2)

Now, the maximum speed will be reached when the potential energy is zero, i.e. when the sping is not stretched, that is when x = 0

With this info we will know at what time it happens:

$0 = x(t) = 0.100cos(\omega t)$

The first time that the cosine is equal to zero is when its argument is equal to π/2

i.e.

$t_{maxV}=\pi /(2\omega)$

And the velocity at that time is:

$\frac{dx}{dt}(t_{maxV} ) =- 0.100\omega sin(\omega t_{maxV})\\\frac{dx}{dt}(t_{maxV} ) =- 0.100\omega sin(\pi/2)\\$

But sin(π/2) = 1.

Therefore, using eq(2):

$\frac{dx}{dt}(t_{maxV} ) = 0.100*\omega = 0.100\frac{\pi}{0.400} = \pi/4$

And so:

$V_{max} = \pi / 4 =0.785$

6 0

2 years ago

A roller coaster car moving at a velocity of 30 meters/second has a momentum of 2.5 _ 104 kilogram meters/second. What is its ma

Vesnalui [34]

Momentum is described as the result of the calculation of mass multiplied by that thing's velocity.

In equational formula we can write it: 

P (momentum) = m(mass) * v(velocity) 

so to find the mass, revert the equation:

P = m v 
m = P / v

now for the value entry,

m = 2.5 * 10^4 kgm/s / 30 m/s 

m = 8,3 * 10^2 kilograms

I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!

8 0

3 years ago

A car goes around in a circular curve on a horizontal road at constant speed. what is the direction of the friction force on the

velikii [3]

Outside. but I may be wrong

3 0

3 years ago