Ask question

Ask question

All categories

svet-max [94.6K]

4 years ago

14

Describe how the size of the force of friction depends on the size of the normal force?

1 answer:

Hoochie [10]4 years ago

7 0

Answer:

mark brainliest

Explanation:

When a greater normal force is exerted, the actual contact area increases, and it is found that the friction is proportional to this area. Two rough surfaces in contact have a much smaller area of actual contact than their total area.

You might be interested in

An 84.0 kg sprinter starts a race with an acceleration of 1.76 m/s2. If the sprinter accelerates at that rate for 11 m, and then

gulaghasi [49]

Answer:

t=17.838s

Explanation:

The displacement is divided in two sections, the first is a section with constant acceleration, and the second one with constant velocity. Let's consider the first:

The acceleration is, by definition:

$a=\frac{dv}{dt}=1.76$

So, the velocity can be obtained by integrating this expression:

$v=1.76t$

The velocity is, by definition: $v=\frac{dx}{dt}$ , so

$dx=1.76tdt\\x=1.76\frac{t^{2}}{2}$ .

Do x=11 in order to find the time spent.

$11=1.76\frac{t^2}{2}\\ t^2=\frac{2*11}{76} \\t=\sqrt{12.5}=3.5355s$

At this time the velocity is: $v=1.76t=1.76*3.5355s=6.2225\frac{m}{s}$

This velocity remains constant in the section 2, so for that section the movement equation is:

$x=v*t\\t=\frac{x}{v}$

The left distance is 89 meters, and the velocity is $6.2225\frac{m}{s}$ , so:

$t=\frac{89}{6.2225}=14.303s$

So, the total time is 14.303+3.5355s=17.838s

7 0

3 years ago

A roller skater of 47kg moving with a velocity of 12 m/s to the east picks up a bag of 6.0 kg. What is the final velocity of the

WITCHER [35]

Answer:

v_f = 10.85 m/s

Explanation:

We will apply the law of conservation of momentum here:

$m_{1}v_{1i} + m_{2}v_{2i} = m_{1}v_{1f}+m_{2}v_{2f}\\$

where,

m₁ = mass of roller skater = 47 kg

m₂ = mass of bag = 6 kg

v_1i = initial speed of roller skater = 12 m/s

v_2i = initial speed of the bag = 0 m/s

v_1f = final speed of the roller skater = ?

v_2f = final speed of the bag = ?

Both the bag and the skater will have same speed at the end because kater is carrying the bag:

v_1f = v_2f = v_f

Therefore, the equation will become:

$(47\ kg)(12\ m/s)+(6\ kg)(0\ m/s)=(47\ kg)(v_{f})+(5\ kg)(v_{f})\\564\ N.s = (47\ kg+5\ kg)(v_{f})\\v_{f} = \frac{564\ N.s}{52\ kg}\\$

<u>v_f = 10.85 m/s</u>

8 0

3 years ago

Which instrument is used to measure heat radiation ?

Anna007 [38]

Geiger counter measures radiation.

6 0

3 years ago

Read 2 more answers

Which of the following could be used as biomass fuel? Check all that apply. A. Rocks B. Corn stalks C. Plastic D. A tree

allsm [11]

Biomass fuel is produced from organic materials. Therefore, B and D apply. This fuel can be created from fertilizer, crops, lumber, etc.

4 0

4 years ago

Read 2 more answers

Photoelectric effect definition

xenn [34]

Photoelectric effect is the emission of electrons by a substance that has been subjected to electromagnetic energy

3 0

4 years ago