Answer:
the human body isn't very efficient at converting food into useful work. The human body is less than 5% efficient most of the time. The rest of the energy is converted to heat, which may or may not be useful, depending on how cool or warm a person wants to be.
Explanation:
Answer: When the car speed triples, momentum also triples but Kinetic energy increases 9 times or by 9 fold.
Explanation:
The momentum of a car (an object) is
p= mv
where
m is =the mass of the object( in this case car)
v is its= velocity
While the kinetic energy is is given by the formulae
K=1/2mv²
To determine how momentum and kinetic energy of the car changes when the speed of the object triples, We have that the new velocity,
v¹= 3v
So that the momentum change becomes
p¹=mv¹=m (3v)= 3mv
mv=p
therefore p¹= 3p
we can see that the momentum also triples.
And the kinetic energy change becomes
K¹=1/2m(v¹)²= 1/2m (3v)²
= 1/2m9v²= 1/2 x m x 9 x v²=9 x1/2mv²
1/2mv²=K
K¹= Kinetic energy = 9k
but Kinetic energy increases 9 times
Answer:
b) Nothing will happen, the sea saw will still be balanced.
Explanation:
b) Nothing will happen, the sea saw will still be balanced.
Reason:-
When two kids are balanced, the sum of torques on the seesaw will be zero.
if each kid, reduces their distances by half, then the torque of each kid will be half and the sum of torque of each on the seesaw will be zero.
Therefore the seesaw is balanced
Answer:
To find out what water is made of, it helps to look at its chemical formula, which is H2O. This basically tells us that the water molecule is composed of two elements: hydrogen and oxygen or, more precisely, two hydrogen atoms (H2) and one oxygen atom (O).
Explanation:
Answer:
F_Balance = 46.6 N ,m' = 4,755 kg
Explanation:
In this exercise, when the sphere is placed on the balance, it indicates the weight of the sphere, when another sphere of opposite charge is placed, they are attracted so that the balance reading decreases, resulting in
∑ F = 0
Fe –W + F_Balance = 0
F_Balance = - Fe + W
The electric force is given by Coulomb's law
Fe = k q₁ q₂ / r₂
The weight is
W = mg
Let's replace
F_Balance = mg - k q₁q₂ / r₂
Let's reduce the magnitudes to the SI system
q₁ = + 8 μC = +8 10⁻⁶ C
q₂ = - 3 μC = - 3 10⁻⁶ C
r = 0.3 m = 0.3 m
Let's calculate
F_Balance = 5 9.8 - 8.99 10⁹ 8 10⁻⁶ 3 10⁻⁶ / (0.3)²
F_Balance = 49 - 2,397
F_Balance = 46.6 N
This is the balance reading, if it is calibrated in kg, it must be divided by the value of the gravity acceleration.
Mass reading is
m' = F_Balance / g
m' = 46.6 /9.8
m' = 4,755 kg
