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
morpeh [17]
3 years ago
9

a 45kg box of books is lifted o a bookself 1.75 m above the floor. how much work was done to lift the books?

Physics
1 answer:
jekas [21]3 years ago
7 0

Answer:

770 J

Explanation:

W = PE

W = mgh

W = (45 kg) (9.8 m/s²) (1.75 m)

W = 770 J

You might be interested in
Suppose you wanted to break a meter stick over your knee. The cross-section of a meter stick is rectangular. Will it be easier t
LenaWriter [7]

Answer:

It will be easier to break the meter rule with the long side against my knee.

Explanation:

To break the meter rule involves the principle of bending moment. The long side will require less force to generate the same amount of bending moment that will have to be generated to break the meter rule. The short side on the other hand will require more force to generate this mount of bending moment. This is because the shorter has a very small surface area, which concentrates the force on your knee. The pressure is then dissipated as more pressure to your knee. Th longer side has a lesser surface area so, most of the force is used in breaking the meter rule.  

6 0
3 years ago
Which of the following is a unit of rotational speed?
gladu [14]
C. Rotations per second
Or normally we'd use Radians Per second  

_Brainliest if helped!!
3 0
3 years ago
In which direction does the sun appear to move across the sky
blsea [12.9K]

Answer:east

Explanation:Earth rotates or spins toward the east, and that's why the Sun, Moon, planets, and stars all rise in the east and make their way westward across the sky.

6 0
3 years ago
Read 2 more answers
What are the two forces that keep a pendulum swinging?
Nezavi [6.7K]
The force of gravity is the only force that keeps a pendulum in motion. both the force increases the speed of the pendulum on the downswing and decreases it's speed on its upswing.
3 0
3 years ago
Read 2 more answers
How was Bohr's atomic model different from those of previous scientists?
exis [7]

Answer:Bohr placed the electrons in distinct energy levels.  Rutherford described the atom as consisting of a tiny positive mass surrounded by a cloud of negative electrons. Bohr thought that electrons orbited the nucleus in quantised orbits.

Explanation: also rutherfords was just a hypothesis while Bhor took the time to make his an experiment

4 0
3 years ago
Other questions:
  • A molecule of water has both partial negative and partial positive charges because _______
    8·1 answer
  • How do electromagnetic forces work?
    8·1 answer
  • Is sharpening a pencil a physical change or chemical change
    15·2 answers
  • Tectonic plates are large segments of the Earth's crust that move slowly. Suppose that one such plate has an average speed of 4.
    14·1 answer
  • Jane has a mass of 40 kg. She pushes on a rock with a force of 100 N. what force does the rock exert on Jane
    5·1 answer
  • A tennis ball is dropped from 1.15 m above the ground. It rebounds to a height of 0.993 m.
    14·1 answer
  • A piece of soft iron is placed in a solenoid increasing the magnetic field in an arrangement that can be switched on and off. Su
    13·1 answer
  • A train moves uniform velocity of 36km/h for 15 sec.find distance
    13·1 answer
  • The results from Rutherford's alpha particle scattering experiment led to
    9·1 answer
  • A car possesses 20 000 units of momentum. What would be the car's new momentum if its mass was doubled
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!