1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Naddika [18.5K]
3 years ago
10

A box (m = 20 kg) is sliding on a horizontal surface. it is connected to a massless hook by a light string passing over a massle

ss pulley wheel. the coefficients of friction between the box and the surface are 0.80 (static) and 0.30 (kinetic). if 15 kg (in total) are placed on the hook, calculate the acceleration of the box.
Physics
1 answer:
Varvara68 [4.7K]3 years ago
5 0

mass of the box = 20 kg

force of friction on the box due to surface

F_s = \mu_s N

F_s = 0.80 * 20 * 9.8

F_s = 156.8 N

similarly kinetic friction on it

F_k = \mu_k N

F_k = 0.30* 20 * 9.8

F_k = 58.8 N

now the weight of the suspended block will be

W = mg = 15*9.8 = 147 N

so here the weight of the suspended block is less than the limiting friction on it

So here we will say that friction will counter balance the weight of the suspended block and it will not move at all

So acceleration of the box will be zero

You might be interested in
Water in the oceans may become fresh water available to humans through the processes of
Darya [45]
<span>Water in the oceans may become fresh water available to humans through the processes of evaporation, condensation and precipitation.

In these processes, water is heated to a very high temperature until it evaporates in order to kill the germs and remove the salts which remains after water evaporation. The next step in condensing the water vapor (which is now fresh) and precipitating this vapor to be used by humans.</span>
4 0
3 years ago
A quarterback passes a football from height h = 2.1 m above the field, with initial velocity v0 = 13.5 m/s at an angle θ = 32° a
alisha [4.7K]

Answer:

a)    x = v₀² sin 2θ / g

b)    t_total = 2 v₀ sin θ / g

c)    x = 16.7 m

Explanation:

This is a projectile launching exercise, let's use trigonometry to find the components of the initial velocity

        sin θ = v_{oy} / vo

        cos θ = v₀ₓ / vo

         v_{oy} = v_{o} sin θ

         v₀ₓ = v₀ cos θ

         v_{oy} = 13.5 sin 32 = 7.15 m / s

         v₀ₓ = 13.5 cos 32 = 11.45 m / s

a) In the x axis there is no acceleration so the velocity is constant

         v₀ₓ = x / t

          x = v₀ₓ t

the time the ball is in the air is twice the time to reach the maximum height, where the vertical speed is zero

          v_{y} = v_{oy} - gt

          0 = v₀ sin θ - gt

          t = v_{o} sin θ / g

         

we substitute

       x = v₀ cos θ (2 v_{o} sin θ / g)

       x = v₀² /g      2 cos θ sin θ

       x = v₀² sin 2θ / g

at the point where the receiver receives the ball is at the same height, so this coincides with the range of the projectile launch,

b) The acceleration to which the ball is subjected is equal in the rise and fall, therefore it takes the same time for both parties, let's find the rise time

at the highest point the vertical speed is zero

          v_{y} = v_{oy} - gt

          v_{y} = 0

           t = v_{oy} / g

           t = v₀ sin θ / g

as the time to get on and off is the same the total time or flight time is

           t_total = 2 t

           t_total = 2 v₀ sin θ / g

c) we calculate

          x = 13.5 2 sin (2 32) / 9.8

          x = 16.7 m

4 0
3 years ago
Order the speed of sound through these materials from the slowest to the fastest.
Sholpan [36]

Speed of sound in cold air < Speed of sound in Warm air < Speed of sound in hot molten lead < Speed of sound in water

Explanation:

Step 1:

Speed of sound in water varies from 1450 to 1498 meters per second

Speed of sound in Hot Molten lead is approximately 1210 meters per second

Speed of sound in warm air is approximately 338.89 meters per second

Speed of sound in cold air is approximately 293.33 meters per second

Step 2:

In warm air sound travels faster than that of sound travelling nature in cold air.

∴ Speed of sound in cold air < Speed of sound in Warm air < Speed of sound in hot molten lead < Speed of sound in water

Speed of sound in cold air the slowest while Speed of sound in water is the fastest mean.

8 0
3 years ago
HEY CAN ANYONE PLS ANSWER DIS!!!!!!!!!!!!!!!
Troyanec [42]

Answer:

Explanation:

you can seperate mixtures  by filtration, evaporation, distillation and chromatography.

3 0
3 years ago
Read 2 more answers
A 63 kg kg person starts traveling from rest down a waterslide 6.0 mm above the ground. At the bottom of the waterslide, it then
gladu [14]

Answer:

change waterslide according to question. and you are good to go. check photo for solve

5 0
3 years ago
Other questions:
  • What is the symbol name?
    10·1 answer
  • Write the equality and conversion factors for the relationship between miles and hours for a car traveling at 55 mi/h
    14·1 answer
  • How do you make magnetic and static forces strong or week?
    6·1 answer
  • Please need help on this I know it’s not D an atom.
    7·1 answer
  • If you had been traveling that fast and the light actually was yellow, what color would it have seemed to you?
    6·1 answer
  • What is the summary for Electrons and protons​
    12·1 answer
  • The volume of a gas is reduced from 4 l to 0.5 l while the temperature is held constant. How does the gas pressure change?
    11·1 answer
  • What is the material ability to be desolved in a solvent
    9·2 answers
  • The actual depth of a shallow pool 1.00 m deep is not the same as the apparent depth seen when you look straight down at the poo
    13·1 answer
  • Which of these structures is an architect most likely to design?
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!