Answer:
If the system consists of the block only, the work done by the gravity is negative.
If the system consists of the block and the earth the work done by the gravity is zero.
Explanation:
If the system consists of the block only, then the system experiences two external forces: one exerted by the hand that lifts the block vertically upward and other exerted by the earth (gravity), which is opposed to the movement of the system, so the work done by gravity is negative.
On the other hand, if the system consists of the block and the earth, then only exists a external force which is the exerted by the hand. So, the force exerted by gravity is zero.
Answer:
Balances and Scales
A balance compares an object with a known mass to the object in question. One example of a balance is the triple beam balance. The standard unit of measure for mass is based on the metric system and is typically denoted as kilograms or grams.
Answer:
Explanation:
ignore air resistance
Let t be the time of fall for the dropped stone.
½(9.8)t² = 43.12(t - 2.2) + ½(9.8)(t - 2.2)²
4.9t² = 43.12t - 94.864 + 4.9(t² - 4.4t + 4.84)
4.9t² = 43.12t - 94.864 + 4.9t² - 21.56t + 23.716
0 = 21.56t - 71.148
t = 71.148/21.56 = 3.3 s
h = ½(9.8)3.3² = 53.361 = 53 m
or
h = 43.12(3.3 - 2.2) + ½(9.8)(3.3 - 2.2)² = 53.361 = 53 m
The velocity of the combination of Jackie and the bicycle is 3.328 m/s.
Explanation:
From the given data the constant kinetic energy is 3.6 J. The mass of combination is 0.65 kg. To find the velocity of the combination of Jackie and the bicycle the formula is
KE = 0.5 x mv2.
To find velocity,
V2=ke/(0.5×m)
V=
v= 3.6/(0.5×0.65)
=
v= 3.328 m/s
Hence, the velocity of the combination of Jackie and the bicycle is 3.328m/s.
According to the information given, the Heisenberg uncertainty principle would be given by the relationship
Here,
h = Planck's constant
= Uncertainty in velocity of object
= Uncertainty in position of object
m = Mass of object
Rearranging to find the position
Replacing with our values we have,
Therefore the uncertainty in position of electron is 
