How can shoe and tire marks be preserved in mud?

A person who normally weighs 580 N is riding in an elevator that is moving upward, but slowing down at a steady rate. If this pe

Zanzabum

Answer:

M au = Fs - M g au = upwards acceleration; Fs = scale reading

Fs = M (au + g) scalar quantities where g is positive downwards and au is positive upwards - Fs is the net force acting on the person

If the acceleration is zero Fs = M g and the scale reads the persons weight

If the elevator is decelerating then au is negative and the scale reading Fs = (g - au) M and the scale reading is less than the weight of the person

5 0

2 years ago

One horse is pulling a 755 kg sled straight ahead applying a force of 1988 N. If the acceleration of the sled is 1.36 m/s2, what

Inessa [10]

Answer:

The coefficient of kinetic friction is 0.13

Explanation:

Newton's second law states that the acceleration of an object is proportional to the net force on it, the factor of proportionality is the mass. So, we can express that law mathematically as:

$\sum\overrightarrow{F}=m\overrightarrow{a}$ (1)

With F the net force, m the mass and a the acceleration of the object. In our case we're interested on what's happening to the sled, then we have to analyze the forces on it, those forces are the weight and the normal force on the vertical direction and the pulling force and frictional force in the horizontal direction. So, because (1) is a vector equation we can express that in their vertical (y) and horizontal (x) components:

$F_y=ma_y$ (2)

$F_x=ma_x$ (3)

On y we have that the acceleration is zero because the sled is not moving upward or downward, remember that the net force on y is the weight (W) pointing downward and the normal force pointing upward:

$F_y=W+n=0$

Following the convention that positive is upward and negative downward, W=mg=(755)(-9.81):

$F_y=(755)(-9.81)+n=0$

$n=7406.55 N$ (4)

Now on the x direction we have the sum of the forces is the pulling force (T) and friction force (f)

$F_x=F+f=ma_x$

Choosing the direction where the horse is pulling F=1988N and the acceleration should be positive too, then:

$1988+f=m(1.36)$

$f=(755)(1.36)-1988=-961.2 N$

The negative sign means it's in the opposite direction the horse is pulling

The frictional force is related with the coefficient of kinetic friction in the next way:

$|f|=\mu_k n$

with μk the coefficient of kinetic friction, and n the normal force that we already found on (4), so we simply solve the last equation for μk:

$\mu_k=\frac{|f|}{n}=\frac{961.2}{7406.55}=0.13$

4 0

4 years ago

In this dark-colored forest, you started with 50% light moths and 50% dark moths. At the end of your simulation, was there a hig

krek1111 [17]

Dark moths because they use their color to blend in with the trees to hide from birds

5 0

2 years ago

How can you increase the momentum of an object

Olin [163]

Answer:

You can change the momentum of an object by giving the object more force or less force.

Explanation:

Think about a ball. It is going slow, you push it and you give it more momentum.

5 0

3 years ago

A train is moving at a speed of 50 km/h. How many hours will it take thetrain to travel 600 kilometers

olga_2 [115]

Answer:

12

Explanation:

600/50 is 12 so the answer is twelve

5 0

3 years ago