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
goblinko [34]
3 years ago
5

You are carrying a 7.0-kg bag of groceries as you walk at constant velocity along the sidewalk. You walk a distance of 82 meters

and hold the bag at a height of 1.5 m above the sidewalk. How much work against gravity do you do on the bag?
100 J

0 J

5600 J

82 J
Physics
1 answer:
MAVERICK [17]3 years ago
7 0

Answer:

0J

Option: B

Explanation:

Work is done when something is moved by the force in the direction of the force. That is the force (e.g., the weight) and the direction the object moves must be aligned for work to be done. In this given condition, the direction is horizontal and the force is downward as its gravity force. That 90° between the two vectors.

The work function is W = m × g ×h × cosθ

\text { Where, in this case theta }=90^{\circ}

Hence,  

Work done = 7 × 9.8 × 1.5 × cos(90)  

Work done = 0 (cos90^{\circ} = 0)

Work done = 0

Therefore work done is 0 J.

You might be interested in
a crane lifts four pallets of bricks each of which weigh 5000 N. the crane lifts each pallet a height of 30m. the crane takes 4
love history [14]

Answer:

625 W

Explanation:

Applying

P = W/t.................... Equation 1

Where p = power, W = Work, t = time

But,

W = Force (F) × distance (d)

W = Fd........................ Equation 2

Substitute equation 2 into equation 1

P = Fd/t.................... Equation 3

From the question,

Given: F = 5000 N, d = 30 m, t = 4 munites = (4×60) seconds = 240 seconds

Substitute these values into equation 3

P = (5000×30)/240

P = 625 Watt

3 0
2 years ago
Which best describes the history of scientific knowledge?
Ipatiy [6.2K]
A path of inferences guided to be cherry picked as for which ones were reasonable and which ones had no ability in the real world to sustain in scientific law
8 0
3 years ago
1)the car's engine power is 44000W. Explain this number in a physical sense
Ratling [72]

Answer:

1) It expresses the rate (top speed) at which it can move with time.

2) P = 20 W

3) h = 18 km

Explanation:

1) Power is the rate of transfer of energy.

⇒ Power = \frac{Energy(or workdone)}{Time}

i.e P = \frac{E}{t}

Thus a car's engine power is 44000W implies that the engine of the car can propel the car at this rate. This expresses the rate (top speed) at which it can move with time.

2) m = 400g = 0.4 kg

    t = 20 s

h = 100m

g = 10 m/s^{2}

P = \frac{mgh}{t}

  = \frac{0.4*10*100}{20}

  = \frac{400}{20}

P = 20 W

3) u = 600 m/s

   g = 10 m/s^{2}

From the third equation of free fall,

V^{2} = U^{2} - 2gh

V is the final velocity, U is the initial velocity, h is the height.

0 = (600)^{2} - 2 x 10 x h

0 = 360000 - 20h

20h = 360000

h = \frac{360000}{20}

  = 18000

h = 18 km

The maximum height of the bullet would be 18 km.

3 0
3 years ago
Select the correct answer. The motion of a car on a position-time graph is represented with a horizontal line. What does this in
enyata [817]

If the car's motion appears as a horizontal line on a <u><em>position-time </em></u>graph, it shows that as time changes, the car's position doesn't change.

This is just a complicated way to say that the car is <em>not moving</em>.<em> (A)</em>

7 0
3 years ago
1. Differentiate between speed and velocity.
Mazyrski [523]

Answer:

1. Speed and velocity both involve a numeric rate describing the distance traveled by a body in a unit of time. However, speed describes the rate of a body traveling in any direction in a unit of time, while velocity describes the rate of a body traveling in a particular direction in a unit of time.

2. Answers may vary, but should resemble the following:

Average velocity explains the velocity the body traveled overall, not taking into consideration each spot in the trip. If a car moves at 65 km/h on average, it may have slowed down for some parts and sped up for others. Overall though, it would have made a certain distance of travel within a specified unit of time that totals the average velocity of 65 km/h.

Instantaneous velocity explains the velocity of a body at a particular instant of the trip. The instantaneous velocity of a car stopped at a stop sign would be 0 m/s even if it was moving before and will continue to move after this stop. The velocity at that particular instant is the instantaneous velocity.

Uniform velocity is when the distance being covered is changing uniformly with time. For example, if a car moves 20 km every 30 minutes and continues to do so in the same direction, it's traveling with a uniform velocity.

3. a=v2−v1t

a=20 m/s−60 m/s6 s

a=−406

a = –6.7 m/s2

4. v2 = v1 + at

v2 = 14 m/s + (3 m/s2 × 6 s)

v2 = 14 + 18

v2 = 32 m/s

5. v=st

v=375 km5 h

v = 75 km/h  

6. First, convert the minutes to seconds. Since there are 60 seconds in one minute, multiply:

60 × 15 (minutes) = 900 seconds

s = v × t

s = 6 m/s × 900 s

s = 5,400 m

7. t=sv

t=80 km35 km/hr

t = 2.29 hr

8. a=v2−v1t

a=50 m/s−15 m/s4 s

a=35 m/s4 s

a = 8.75 m/s2

9. vav=v1+v22

vav=15 m/s+50 m/s2

vav=65 m/s2

vav = 32.5 m/s

10. a=v2−v1t

a=0 m/s−11.5 m/s3.5 s

a = –3.29 m/s2

Explanation:

7 0
3 years ago
Other questions:
  • A length of copper wire has a resistance 29 Ω. The wire is cut into three pieces of equal length, which are then connected as pa
    6·1 answer
  • The left face of a biconvex lens has a radius of curvature of magnitude 11.7 cm, and the right face has a radius of curvature of
    14·1 answer
  • which of this is not example of simple machine? A) a crowbar,B)a knife,C)a bicycle,D)a wheelchair ramp
    11·1 answer
  • Calculating Displacement from the Area under a Curve Try Use the graph to answer the question What is the total displacement of
    8·1 answer
  • In a skating stunt known as "crack-the-whip," a number of skaters hold hands and form a straight line. They try to skate so that
    14·1 answer
  • A physical pendulum consists of a uniform solid disk (of radius R 2.35 cm) supported in a vertical plane by a pivot located a di
    10·1 answer
  • A small charged sphere is attached to a thread and placed in an electric field. The other end of the thread is anchored so that
    11·1 answer
  • Yellow-green light has a wavelength of 560 nm. What is its frequency?
    10·2 answers
  • 2.If you increase the release helght, you are increasing the what
    5·1 answer
  • Two gliders on an air track collide in a perfectly elastic collision. Glider A has a mass of 1.1 kg and is initially travelling
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!