A group of protons and neutrons surrounded by electrons
Answer:
Wear a helmet. Stay visible; use bike lights and/or wear bright clothes. Look and Signal; use hand signals to let drivers know where you're going, try to make eye contact with them and look before you go.
Explanation:
Answer:
Increase in mass and height
Explanation:
The gravitational potential energy of an object can increase if the mass and height of object is increased.
Gravitational potential energy is the energy due to the position of a body.
It is expressed as:
Gravitational potential energy = mass x acceleration due gravity x height
Increasing mass and height will cause an increase in gravitational potential energy.
Answer:
9727160J
Explanation:
Given parameters:
Height of elevator rise = 436m
Force exerted = 22310N
Unknown:
Work done by the elevator lifting mechanism = ?
Solution:
The work done by a body is the force applied to move a body in a specific direction;
Work done = force x distance moved
In this case, the force and distance moved is provided already;
Work done = 22310 x 436 = 9727160J
Answer:
Explanation:
Given that
The mass of the body is 0.04kg
M=0.04kg
The radius of the paths is 0.6m
r=0.6m
The normal force exerted at A is 3.9N
Fa=3.9N
The normal force exerted at B is 0.69N
Fb=0.69N
Then work done by friction from point A to B will be the change in K.E
W=∆K.E+P.E
So we need to know the velocity at both point A and B
Then since the centripetal force is given as
Ft=mv²/r
Then,
For point A
Fa=mv²/r
3.9=0.04v²/0.6
3.9=0.0667v²
v²=3.9/0.0667
v²=58.5
v=√58.5
v=7.65m/s
Va=7.65m/s
Now at point B
Fb=mv²/r
0.69=0.04v²/0.6
0.69=0.0667v²
v²=0.69/0.0667
v²=10.35
v=√10.35
v=3.22m/s
Vb=3.22m/s
Then, the work done is
W=∆K.E+P.E
P.E is given as mgh
The height will be 2R =1.2m
P.E=mgh
P.E=0.04×9.81×1.2
P.E=0.471J
Final kinetic energy at B minus initial kinetic energy at A
W=K.Eb-K.Ea
K.E is given as 1/2mv²
W=1/2m(Vb²-Va²) +P.E
W=0.5×0.04(3.22²-7.65²) +0.471
W=0.5×0.04×(-48.1541) +0.471
W=-0.96+0.471
W=-0.49J
work was done on the block by friction during the motion of the block from point A to point B is 0.49J.
Friction opposes motions and that is why the work done is negative
