Answer:
work done lifting the bucket (sand and rope) to the top of the building,
W=67.46 Nm
Explanation:
in this question we have given
mass of bucket=20kg
mass of rope=
height of building= 15 meter
We have to find the work done lifting the bucket (sand and rope) to the building =work done in lifting the rope + work done in lifting the sand
work done in lifting the rope is given as,
=
..............(1)
=
=22.5 Nm
work done in lifting the sand is given as,
.................(2)
Here,
F=mx+c
here,
c=20-18
c=2
m=
m=.133
Therefore,

Put value of F in equation 2


Therefore,
work done lifting the bucket (sand and rope) to the top of the building,
W=22.5 Nm+44.96 Nm
W=67.46 Nm
Q 24: Newton's first law of motion states that anything that stands still will stay still unless unbalanced force is acted upon that object. Newton's second law of motion states that the velocity of an object changes when subjected to external Force. Newton's third law of motion says that for every action there is an equal and opposite reaction. when bumper cars crash into each other one car goes one way and the other goes the other way.
Q 25: if the bumper cars doubled their Mass the motion would be halfed but if the net force is doubled the motion will double.
made from pure metals . . . no;
they've been made from all kinds of weird compounds and alloys.
conduct electricity with zero resistance . . . yes;
that's why they're called "superconductors".
produce a strong magnetic field . . . possible, but not because it's a superconductor;
just like any other conductor, the magnetic field depends on the current that's flowing in the conductor.
no loss of energy in the transfer of electricity . . .
there's no loss of energy in the current flowing in the superconductor;
but if you tried to transfer the current out of the superconductor into
something else, then there would be some loss.
Answer:
a neutral atom doesn't have a charge and an ion does.
Explanation:
When atoms bond they can gain or lose electrons which gives them a charge.
anion = negatively charged ion
cation = positively charged ion
Answer:
250 N
433 N
Explanation:
N = Normal force by the surface of the inclined plane
W = Weight of the block = 500 N
f = static frictional force acting on the block
Parallel to incline, force equation is given as
f = W Sin30
f = (500) Sin30
f = 250 N
Perpendicular to incline force equation is given
N = W Cos30
N = (500) Cos30
N = 433 N