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
Artyom0805 [142]
2 years ago
5

The floor of a railroad flatcar is loaded with loose crates having a coefficient of static friction of 0.320 with the floor. If

the train is initially moving at a speed of 49.0 km/h, in how short a distance can the train be stopped at constant acceleration without causing the crates to slide over the floor?
Physics
1 answer:
mart [117]2 years ago
5 0

Answer:  29.50 m

Explanation: In order to calculate the higher accelation to stop a train  without moving the crates inside the wagon which is traveling at constat speed we have to use the second Newton law so that:

f=μ*N the friction force is equal to coefficient of static friction  multiply the normal force (m*g).

f=m.a=μ*N= m*a= μ*m*g= m*a

then

a=μ*g=0.32*9.8m/s^2= 3.14 m/s^2

With this value we can determine the short distance to stop the train

as follows:

x= vo*t- (a/2)* t^2

Vf=0= vo-a*t then t=vo/a

Finally; x=vo*vo/a-a/2*(vo/a)^2=vo^2/2a= (49*1000/3600)^2/(2*3.14)=29.50 m

You might be interested in
Someone please help ! this is worth 40 points!!
makvit [3.9K]

Explanation:

  1. non uniform motion
  2. F=ma, 1=m(1), m=1Kg
5 0
2 years ago
Please help answer question​
nika2105 [10]

Answer:

C = 1.01

Explanation:

Given that,

Mass, m = 75 kg

The terminal velocity of the mass, v_t=60\ m/s

Area of cross section, A=0.33\ m^2

We need to find the drag coefficient. At terminal velocity, the weight is balanced by the drag on the object. So,

R = W

or

\dfrac{1}{2}\rho CAv_t^2=mg

Where

\rho is the density of air = 1.225 kg/m³

C is drag coefficient

So,

C=\dfrac{2mg}{\rho Av_t^2}\\\\C=\dfrac{2\times 75\times 9.8}{1.225\times 0.33\times (60)^2}\\\\C=1.01

So, the drag coefficient is 1.01.

4 0
2 years ago
Raul dug a hole in his yard to repair a water pipe. It took him 2 seconds to apply a force of 50 Newtons to push the shovel 0.25
Sergeu [11.5K]

Answer:

Option B. 6.25 J/S

Explanation:

Data obtained from the question include:

t (time) = 2secs

F (force) = 50N

d (distance) = 0.25m

P (power) =?

The power can be obtained by using the formula P = workdone/time.

P = workdone / time

P = (50 x 0.25)/ 2

P = 6.25J/s

3 0
2 years ago
The slope of a distance-time graph will give
Dafna1 [17]
5.
explanation: the answer is 5
5 0
3 years ago
Which of the following is the best reason to rest muscle groups between workouts?
vovangra [49]

Answer;

It allows the muscles time to heal.

Explanation;

-It is very important to rest muscles between workouts. In fact, resistance training breaks down muscles causing microscopic tears. It is only during rest when the muscle-building process is stimulated and the regeneration of new tissue occurs.

-But when muscles are not allowed adequate rest and recover time, the regeneration process cannot occur. This can have several side effects such as increased soreness, decreased strength and performance, and may lead to injury.  

4 0
3 years ago
Read 2 more answers
Other questions:
  • A block of wood 3.0 cm on each side has a mass of 27g. what is the density of this block?
    10·1 answer
  • Five hundred joules of heat are added to a closed system. The initial internal energy of the system is 87 J, and the final inter
    10·2 answers
  • a stone is dropped into a deep well and is heard to hit the water 3.41 s after being dropped. determine the depth of the well. .
    10·1 answer
  • How would life on earth be different if earth’s axis were not tilted with respect to its orbit?
    5·2 answers
  • Which statement best describes the kinetic theory of matter?
    14·2 answers
  • Frost wedging in a sentence
    5·1 answer
  • Which tools would be use to find an irregularly shaped object’s mass and volume?
    11·1 answer
  • A car accelerates uniformly from rest at a speed of 1.67 ft s^2 over a distance of 5 yards.What is the acceleration of a car?
    15·2 answers
  • People will form relationships with others who are similar in __________.
    14·2 answers
  • Two students were climbing stairs at school. Student 1 has a weight of 700 N. Student 2 has a weight of 650 N. How much power wo
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!