PHYSICS HIGH SCHOOL

Kelly carried a box weighing 10 N the 200 meters from his car to his new house.  George took the box from Kelly and carried it up the 3 meter tall flight of stairs.  Who did more work?

Answers

Answer 1
Answer: While moving box from car to house
W = F * d * cosine (90 degree)
= 10N * 200m * 0 
= 0Nm

While lifing 3m tall flight of stairs
W=F*d*cosine(0 degree)
= 10N * 3m
= 300 Nm

George did more work
Answer 2
Answer:

I think George did more work because George moved the box to the same direction as the force that he applied. So he is applying an upward force to the box to keep it from falling down and moving to the box up the stairs and Kelly does move the box farther than George, but he isn´t doing any work before the force he applies to the box on a different direction than movement.


Hope this helps


Tobey


Related Questions

HIGH SCHOOL

Arrange the following parts in the order that matches the light path through a light microscope: specimen, ocular lens, objective lens, body tube, light source.

Answers

From the top downward:

Ocular lens (eyepiece)
Body tube
Objective lens
Specimen
Light source
MIDDLE SCHOOL

What does set up transformer do? Set down transform

Answers

A step-up transformer is used to increase the voltage and reduce the current. The voltage is increased from about 25,000 Volts (V) to 400,000 V causing the current to decrease. Less current means less energy is lost through heating the wire. To keep people safe from these high voltage wires, pylons are used to support transmission lines above the ground.
Before reaching the end user, a step-down transformer, reduces the voltage from the transmission voltage to the safer voltage of 230 V for home use.
MIDDLE SCHOOL

Describe a situation where kinetic energy is converted into potential energy

Answers

1. A spring or elastic can be stretched to store energy as it wants to return to rest.

2. Gravitational every can be is stored by moving a ball against gravity when lifted then released when bounced.

3. Separating two charged plates will store energy as the plates want to return to their original position. 


COLLEGE

A Honda Civic travels in a straight line along a road. Its distance x from a stop sign is given as a function of time t by the equation x(t)= α t2− β t3, where α = 1.44 m/s2 and β = 5.00×10−2 m/s3 a. Calculate the average velocity of the car for the time interval t=0 to t1 = 1.95 s .

b. Calculate the average velocity of the car for the time interval t=0 to t2 = 3.96 s .

c. Calculate the average velocity of the car for the time interval t1 = 1.95 s to t2 = 3.96 s .

Answers

Answer:

a) Average velocity of the car for the time interval t=0 to t = 1.95 s is 2.62 m/s.

b) Average velocity of the car for the time interval t=0 to t = 3.96 s is 4.92 m/s.

c) Average velocity of the car for the time interval t=1.95 to t = 3.96 s is 7.15 m/s.

Explanation:

We have  x(t)= α t²− β t³

That is x(t)= 1.44 t²− 5 x 10⁻² t³

Average velocity is ratio of distance traveled to time.

a)Average velocity of the car for the time interval t=0 to t = 1.95 s

  x (0) = 1.44 x 0²− 5 x 10⁻² x 0³ = 0 m

  x (1.95) = 1.44 x 1.95²− 5 x 10⁻² x 1.95³ = 5.10 m

  Time difference = 1.95 - 0 = 1.95 s

  Average velocity

b)Average velocity of the car for the time interval t=0 to t = 3.96 s

  x (0) = 1.44 x 0²− 5 x 10⁻² x 0³ = 0 m

  x (3.96) = 1.44 x 3.96²− 5 x 10⁻² x 3.96³ = 19.48 m

  Time difference = 3.96 - 0 = 3.96 s

  Average velocity

c)Average velocity of the car for the time interval t=0 to t = 3.96 s

  x (1.95) = 1.44 x 1.95²− 5 x 10⁻² x 1.95³ = 5.10 m

  x (3.96) = 1.44 x 3.96²− 5 x 10⁻² x 3.96³ = 19.48 m

  Time difference = 3.96 - 1.95 = 2.01 s

  Average velocity

COLLEGE

The 2-Mg car is being towed by a winch. If the winch exerts a force of T=100(s+1)N on the cable, where s is the displacement of the car in meters, determine the speed of the car when s=10m, starting from rest. Neglect rolling resistance of the car.

Answers

Answer:

The speed of the car = 3.32 m/s

Explanation:

Speed: This can be defined as the rate of change of distance. The S.I unit of speed is m/s.

Note: From the question, The force acting on the car through the winch = The tension on the cable.

F = T = ma..................... Equation 1

Where F = Force on the car, T = tension on the cable, m = mass of the car, a = acceleration of the car.

Where T = 100(s+1) N,

100(s+1) = ma ......................... Equation 2

making a the subject of equation 2

a = 100(s+1)/m ...................... Equation 3.

When s = 10 m, m = 2 Mg = 2×10³ kg = 2000 kg

a = 100(10+1)/2000

a = 0.55 m/s²

Using

v² = u²+2as........................... Equation 4

Where a = 0.55 m/s², s = 10 m, u = 0 m/s

Substituting into equation 4

v² = 0² + 2(0.55)(10)

v² = 11

v = √11

v = 3.316

v ≈ 3.32 m/s.

Thus the speed of the car = 3.32 m/s

HIGH SCHOOL

Ft-Fg= ma solve for a

Answers

Ft - Fg = ma   Divide both sides by m
= a   Switch the sides to make it easier to read
a =  
The answer is a= Ft-Fg/m
MIDDLE SCHOOL

A dog pulls on a pillow with a force of 5 N at an angle of 37o to the horizontal. Find the x and y components of this force.​

Answers

Answer:

x- component = Fx= 4N

y - component= Fy= 3N

Explanation:

Fx=Fcos∅= 5cos 37= 3.99≅4N

Fy=F sin∅= 5 Sin37= 3.009≅3.01N

the dog pulls the pillow at an angle 37 degrees to the horizontal means it pulls it at an angle 37 degrees with the x- axis.if  the line of the force represents the vector F then its horizonatal and vertical components wil be along x-axis and y-axis ie Fx and Fy.

as sin∅= Perpendicular/ Hypotenuse

but we have force F and Fy

so sin∅= Fy/F

or Fy= Fsin∅---------eqA

similarly cos∅= base /hpotenuse

cos∅= Fx/F

Fx= Fcos∅----------eq B

eq A  and eq B can be used to determine the values of the rectangular components of the force making an angle with the horizontal

MIDDLE SCHOOL

Which statement about distance and displacement is correct? Distance does not take direction of motion into account, but displacement does.


Displacement does take direction of motion into account but, but distance does.


Both distance and displacement must take direction of motion into account.

Answers

Answer:

Distance does not take direction of motion into account, but displacement does.

Explanation:

Distance is said to be how much ground an object covers during motion. Distance is a scalar quantity. Distance has magnitude but no direction. It only concerns how much ground an object covers without considering the start or end points. For example a person covering a distance from point A to B can be computed without considering it starting and ending point. The distance from A to B can be computed as 100 meters.The change in position is not considered, only the distance it covered(100 meters)

While

Displacement is the change in position of an object. Displacement is a vector quantity as it incorporates both direction and magnitude. Displacement considers the starting and ending points of an object in motion.  Example a person moving from point A to B, the change in position from point A to B shows their is a displacement.

Answer:

The answer i believe is A..

Explanation:

.

COLLEGE

future changes in the environment can best be predicted from data that are: cyclic/highly variable and over long/short periods of time ?

Answers

Answer:

Cyclic and over long periods of time

Explanation:

The extraction and use of scientific data is of paramount importance. This is because of the importance of future decisions based on the data. In prediction the future trends of data, the long-term application need to be taken into consideration. This means that the  data needs to be cyclic, that is, can be applied using models. In addition, because of the future nature of the data, the data has to be used over a long period of time.  

Cyclic and collected over long periods of time
Random Questions