The sound waves travel because of the pitch of the note so the window rattles.
Answer:
1.The force required to stop the shopping cart is, F = 12.25 N
Explanation:
Given data,
The mass of the shopping cart, m = 7 kg
The initial velocity of the shopping cart, u = 3.5 m/s
The final velocity of the shopping cart, v = 0 m/s
The time period of acceleration, t = 2 s
The change in momentum of the cart,
p = m(u - v)
= 7 (3.5 - 0)
= 24.5 kg m/s
The force is defined as the rate of change of momentum. To stop the shopping cart, the force required is given by the formula
F = p / t
= 24.5 / 2
= 12.25 N
Hence, the force required to stop the shopping cart is, F = 12.25 N
2.
We have: F = m × v/t
Here, m = 8500 Kg
v = 20 m/s
t = 10 s
Substitute their values into the expression,
F = 8500 × 20/10
F = 8500 × 2
F = 17000 N
In short, final answer would be 17000 N
Hope this helps!!
I understand that electric field can exist without any magnetic field, although it is also generated by varying magnetic field, but as much I know, magnetic fields don't exist independently, they are generated by varying electric field or moving charge. Even in any magnetic substance, magnetic field is generated due to electrons orbiting the nucleus, and electrons have their own electric field, so electric field is present there as well.
The answer is b) false. Stars are mainly classified by their spectra (the elements they absorb) and their temperature.
Answer:
Explanation:
Work in pumping water from the tank is given as
W = ∫ y dF. From a to b
Where dF is the differential weight of the thin layer of liquid in the tank, y is the height of the differential layer
a is the lower limit of the height
b is the upper limit of the height.
We know that, .
F = ρVg
Where F is the weight
ρ is the density of water
V is the volume of water in tank
g is the acceleration due to gravity
Then,
dF = ρg ( Ady)
We know that the density and the acceleration due to gravity is constant, also the base area of the tank is constant, only the height that changes.
Then,
ρg = 62.4 lbs/ft³
Area = L×B = 3 × 9 = 27ft²
dF = ρg ( Ady)
dF = 1684.8dy
The height reduces from 12ft to 0ft
Then,
W = ∫ y dF. From a to b
W = ∫ 1684.8y dy From 0 to 12
W = 1684.8y²/2 from 0 to 12
W = 842.4 [y²] from y = 0 to y = 12
W = 842.4 (12²-0²)
W = 121,305.6 lb-ft
