PHYSICS COLLEGE

When the sum of all the forces acting on a block on an inclined plane is zero, the blockA) must be at rest
B) must be accelerating
C) may be slowing down
D) may be moving at constant speed

Answers

Answer 1
Answer:

Answer:

hmmm thats too hard for me.

Explanation:

Related Questions

In an electric circuit, resistance and current are ____A. directly proportional B. inversely proportional C. have no effect on each other
A baseball player standing on a platform throws a baseball out over a level playing field. The ball is released from a point 3.50 m above the field with an initial speed of 14.3 m/s at an upward angle of 27.0 degrees above the horizontal. What horizontal distance will the ball travel before hitting the ground?
Which of the following statements correctly compares the relationship between the earth, its atmosphere and radiation?1. The earth is cooled and its atmosphere is heated by solar radiation. 2. The earth is heated and its atmosphere is cooled by terrestrial radiation. 3. The earth is cooled and its atmosphere is heated by terrestrial radiation. 4. The earth is heated and its atmosphere is cooled by solar radiation. Don't answer unless you know for sure. Thank you so much!
Twopucksofequalmasscollideonafrictionlesssurface,asillustratedinthefigure.Immediatelyafterthe collision, the speed of the black puck is 1.5 m/s. What is the speed of the white puck immediately after the collision?
A person on a rocket traveling at 0.47 c (with respect to the Earth) observes a meteor come from behind and pass her at a speed she measures as0.47 c.How fast is the meteor moving with respect to the Earth?

So to deal with the irrational belief in REBT, we must Group of answer choices

A. Consult with a friend and get their feeback

B. Dispute the beliefs by asking if these are true and examining the evidence

C. Seek mental health counseling

D. It is just too hard so let's just forget it.

Answers

Answer:

i believe the answer is B

Explanation:

Seeking the right answer is the best thing to do

Light with a wavelength of 495 nm is falling on a surface and electrons with a maximum kinetic energy of 0.5 eV are ejected. What could you do to increase the maximum kinetic energy of electrons to 1.5 eV?

Answers

Answer:

To increase the maximum kinetic energy of electrons to 1.5 eV, it is necessary that ultraviolet radiation of 354 nm falls on the surface.

Explanation:

First, we have to calculate the work function of the element. The maximum kinetic energy as a function of the wavelength is given by:

K_(max)=(hc)/(\lambda)-W

Here h is the Planck's constant, c is the speed of light, \lambda is the wavelength of the light and W the work function of the element:

W=(hc)/(\lambda)-K_(max)\nW=((4.14*10^(-15)eV\cdot s)(3*10^8(m)/(s)))/(495*10^(-9)m)-0.5eV\nW=2.01eV

Now, we calculate the wavelength for the new maximum kinetic energy:

W+K_(max)=(hc)/(\lambda)\n\lambda=(hc)/(W+K_(max))\n\lambda=((4.14*10^(-15)eV\cdot s)(3*10^8(m)/(s)))/(2.01eV+1.5eV)\n\lambda=3.54*10^(-7)m=354*10^(-9)m=354nm

This wavelength corresponds to ultraviolet radiation. So, to increase the maximum kinetic energy of electrons to 1.5 eV, it is necessary that ultraviolet radiation of 354 nm falls on the surface.

An electric generator contains a coil of 140 turns of wire, each forming a rectangular loop 71.2 cm by 22.6 cm. The coil is placed entirely in a uniform magnetic field with magnitude B = 4.32 T and initially perpendicular to the coil's plane. What is in volts the maximum value of the emf produced when the loop is spun at 1120 rev/min about an axis perpendicular to the magnetic field?

Answers

Answer:

11405Volt

Explanation:

To solve this problem it is necessary to use the concept related to induced voltage or electromotive force measured in volts. Through this force it is possible to maintain a potential difference between two points in an open circuit or to produce an electric current in a closed circuit.

The equation that allows the calculation of this voltage is given by,

\epsilon = BAN \omega

Where

B = Magnetic field

A= Area

N = Number of loops

\omega= Angular velocity

Our values previously given are:

N = 140

A = 71.2*10^(-2)m*22.6*10^(-2)m=0.1609m^2

B = 4.32 T

\omega = 1120 rev / min

We need convert the angular velocity to international system, then

\omega = 1120 rev/min

\omega = 1120rev/min*(2\pi)/(1rev)*(1min)/(60sec)

\omega = 117.2rad/s

Applying the equation for emf, we replace the values and we will obtain the value.

\epsilon = BAN \omega

\epsilon = (4.32)(0.1609)(140)*117.2

\epsilon = 11405Volt

A helium balloon ride lifts up passengers in a basket. Assume the density of air is 1.28 kg/m3 and the density of helium in the balloon is 0.18 kg/m3. The radius of the balloon (when filled) is R = 4.9 m. The total mass of the empty balloon and basket is mb = 121 kg and the total volume is Vb = 0.073 m3. Assume the average person that gets into the balloon has a mass mp = 73 kg and volume Vp = 0.077 m3. 1)What is the volume of helium in the balloon when fully inflated? m3 2)What is the magnitude of the force of gravity on the entire system (but with no people)? Include the mass of the balloon, basket, and helium. N

Answers

Answer:

1) The volume of helium in the ballon when is fully inflated is 492.8070 m³

2) The magnitude of the force of gravity (with no people) is 869.3119 N

Explanation:

Given:

ρair = density of air = 1.28 kg/m³

ρhelium = density of helium = 0.18 kg/m³

R = radius of balloon = 4.9 m

mtotal = 121 kg

Vtotal = 0.073 m³

mp = average mass per person = 73 kg

Vp = 0.077 m³

g = gravity = 9.8 m/s²

Questions:

1) What is the volume of helium in the balloon when fully inflated, Vhelium = ?

2) What is the magnitude of the force of gravity on the entire system (but with no people), Fg = ?

1) The volume of helium in the ballon when is fully inflated

V_(helium) =(4)/(3) \pi R^(3) =(4)/(3) \pi *4.9^(3) =492.8070m^(3)

2) First, you need to calculate the mass of helium

m_(helium) =\rho _(helium) *V_(helium) =0.18*492.8070=88.7053kg

The magnitude of the force of gravity (with no people)

F_(g) =m_(helium) *g=88.7053*9.8=869.3119N

find the area of a right triangle with sides 15.0 cm, 20.0 cm, and 25.0 cm. express your answer with the correct number of significant figures

Answers

The area of this triangle can be calculated using herons formula since th three sides are given. It is expressed as:

A=sqrt( s(s-a)(s-b)(s-c))

where s is equal to a+b+c / 2

s=15 +20 +25 /2=30
A=sqrt( 30(30-15)(30-20)(30-25))
A= 150 cm^3

If i throw up an object up at 31 m/s, how long will it take to get to its highest point

Answers

Answer:

Explanation:

vf=vi+at

vf=31 m/s

vi=0 m/s

a=g=9.8 m/s2

t=?

vf-vi=at

vf-vi/a=t

t=vf-vi/a

t=31 m/s-0/9.8

t=3.16 s
Other Questions
Before the development of quantum theory, Ernest Rutherford's experiments with gold atoms led him to propose the so-called Rutherford Model of atomic structure. The basic idea is that the nucleus of the atom is a very dense concentration of positive charge, and that negatively charged electrons orbit the nucleus in much the same manner as planets orbit a star. His experiments appeared to show that the average radius of an electron orbit around the gold nucleus must be about 10−1010−10 m. Stable gold has 79 protons and 118 neutrons in its nucleus. What is the strength of the nucleus' electric field at the orbital radius of the electrons? What is the kinetic energy of an electron in a circular orbit around the gold nucleus?
A ​46-ton monolith is transported on a causeway that is 3500 feet long and has a slope of about 3.7. How much force parallel to the incline would be required to hold the monolith on this​ causeway?
Coach ulcer paces the sidelines. Sarting at the 30 yd. line (A), he moves to the 10 yd. line (B), back to the 50 yd. line (C) and finally to the 20yd. Line (D) in 200 seconds. Determine his average speed and velocity.
How many different uniquecurrents will there be in this circuit? How many different "branch" are there in this circuit where the currents could differ.