answer.
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
Dafna11 [192]
2 years ago
3

One end of a horizontal spring with force constant 130.0 N/m is attached to a vertical wall. A 4.00-kg block sitting on the floo

r is placed against the spring. The coefficient of kinetic friction between the block and the floor is
μk= 0.400. You apply a constant force F, which is directed toward the wall. F has magnitude of 82.0 N and is directed toward the wall. At the instant that the spring is compressed 80.0 cm, what are

(a) the speed of the block, and
(b) the magnitude and direction of the block's acceleration?
Physics
1 answer:
soldi70 [24.7K]2 years ago
6 0

Answer:

Explanation:

spring constant, K = 130 N/m

mass of block, m = 4 kg

coefficient of friction, μk = 0.4

Force, F = 82 N

compression in spring, d = 80 cm = 0.8 m

(a) Let the speed of the block is v.

Use conservation of energy

F x d = 0.5 Kd² + 0.5mv² + μkmgd

2Fd - Kd² - 2 μk mgd = mv²

4 v² = 2 x 82 x 0.8 - 130 x 0.8 x 0.8 - 2 x 0.4 x 4 x 9.8 x 0.8

4v² = 131.2 - 83.2 - 25.088

v² = 5.728

v = 2.4 m/s

(b)

Net force, Fnet = F - friction force - Kd

Fnet = 82 - 0.4 x 4 x 9.8 - 130 x 0.8

Fnet = - 37.68 N

Acceleration of the block, a = Fnet / m

a = - 37.68 / 4

a = - 9.42 m/s²

the direction of acceleration is opposite to the direction of motion

You might be interested in
A sound technician is testing the sound acoustics in a theatre for an upcoming music concert. As he moves towards the speakers,
Harlamova29_29 [7]

Answer: Increase in wave frequency

Explanation:

When we talk about acoustics we are dealing with sound waves, and one of their main components along with the velocity and wavelength is the <u>frequency.</u>

In this sense, the frequency of any wave refers to how fast (or slow) a wave oscillates. For example, in the especific case of sound waves when the oscillation is faster, the frequency is higher and the pitch gets higher as well.

6 0
2 years ago
Read 2 more answers
If a 3-kg rabbit's leg muscles act as imperfectly elastic springs, how much energy will they hold if the rabbit lands from a hei
DiKsa [7]

Answer;

- 15 J

Explanation;

-Potential energy is defined as mechanical energy, stored energy, or energy caused by its position.

-For the gravitational force the formula is P.E. = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m /s² at the surface of the earth) and h is the height in meters.

Potential energy of the rabbit at the peak of its height is

PE = (3)(10)(0.5) = 15 J

(around 14.7 but because energy is lost, it is less than that)

3 0
2 years ago
Read 2 more answers
Write a hypothesis about the effect of the fan speed on the acceleration of the cart. Use the "if . . . then . . . because . . .
iragen [17]
As an object accelerates i.e., change it's velocity(either direction or speed), the position of the object depends on two factor; If the acceleration was direction based then it might have a zero displacement for eg: if it travels in circle. or it might have a net displacement if it travels in a straight line, quantitatively
s = ut +  \frac{1}{2} at {}^{2}
where,
s = displacement
u = initial velocity
v = final velocity
a = acceleration
t = time

Now, for the hypothesis;
There is no direct relationship between fan speed and acceleration but anyways generally speaking if we do have a relationship that with more fan speed we have a larger displacement of air i.e., a more force i.e., greater acceleration
Thus, it can be said, well not exactly scientific, that with a greater fan speed there will be greater acceleration. if fan speed is increased then acceleration will be more.
:)
8 0
2 years ago
Read 2 more answers
Ronald likes to use his erector set more than anything else.
Rashid [163]
C: Foreclosure. People in identity foreclosure have committed to an identity too soon. Often they have simply adopted the identity of a parent, close relative or respected friend.
5 0
2 years ago
Read 2 more answers
The newly formed xenon nucleus is left in an excited state. Thus, when it decays to a state of lower energy a gamma ray is emitt
nevsk [136]

Answer:3.87*10^-4

Explanation:

What is the decrease in mass, delta mass Xe , of the xenon nucleus as a result of this deca

We have been given the wavelength of the gamma ray, find the frequency using c = freq*wavelength.

C=f*lambda

3*10^8=f*3.44*10^-12

F=0.87*10^20 hz

Then with the frequency, find the energy emitted using equation

E=hf E = freq*Plank's constant

E=.87*10^20*6.62*10^-34

E=575.94*10^(-16)

With this energy, convert into MeV from joules.

With the energy in MeV, use E=mc^2 using c^2 = 931.5 MeV/u.

Plugging and computing all necessary numbers gives you

3.87*10^-4 u.

6 0
2 years ago
Other questions:
  • Will two separate 50db sounds together constitute a 100db sound explain mathematical
    13·1 answer
  • A 4.0 Ω resistor, an 8.0 Ω resistor, and a 12.0 Ω resistor are connected in parallel across a 24.0 V battery. What is the equiva
    14·2 answers
  • At constant temperature, the volume of the container that a sample of nitrogen gas is in is doubled. As a result the pressure of
    5·1 answer
  • Suppose that a rectangular toroid has 2,000 windings and a self-inductance of 0.060 H. If the height of the rectangular toroid i
    13·1 answer
  • A wildlife researcher is tracking a flock of geese. The geese fly 4.0 km due west, then turn toward the north by 40° and fly ano
    13·1 answer
  • Maria throws an apple vertically upward from a height of 1.3 m with an initial velocity of +2.8 m/s. Will the apple reach a frie
    13·1 answer
  • A ball is thrown upward from the top of a 25.0 m tall building. The ball’s initial speed is 12.0 m/sec. At the same instant, a p
    10·1 answer
  • The seeds were sown (change the voice)​
    15·1 answer
  • A 12.0 kg mass, fastened to the end of an aluminum wire with an unstretched length of 0.50 m, is whirled in a vertical circle wi
    7·2 answers
  • a) Suppose that the current in the solenoid is I(t). Within the solenoid, but far from its ends, what is the magnetic field B(t)
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!