Answer: 1.14 N
Explanation :
As any body submerged in a fluid, it receives an upward force equal to the weight of the fluid removed by the body, which can be expressed as follows:
Fb = δair . Vb . g = 1.29 kg/m3 . 4/3 π (0.294)3 m3. 9.8 m/s2
Fb = 1.34 N
In the downward direction, we have 2 external forces acting upon the balloon: gravity and the tension in the line, which sum must be equal to the buoyant force, as the balloon is at rest.
We can get the gravity force as follows:
Fg = (mb +mhe) g
The mass of helium can be calculated as the product of the density of the helium times the volume of the balloon (assumed to be a perfect sphere), as follows:
MHe = δHe . 4/3 π (0.294)3 m3 = 0.019 kg
Fg = (0.012 kg + 0.019 kg) . 9.8 m/s2 = 0.2 N
Equating both sides of Newton´s 2nd Law in the vertical direction:
T + Fg = Fb
T = Fb – Fg = 1.34 N – 0.2 N = 1.14 N
Answer:
P = 800 Pa
Explanation:
The pressure of water at the bottom of the pot can be given by the following formula:
where,
P = Pressure at the bottom of the pot = ?
ρ = density = 1000 kg/m³
h = height of water = 8 cm = 0.08 m
Therefore,
<u>P = 800 Pa </u>
Answer:
(A) The force would be lower on the school day than the weekend.
Explanation:
In a school day the bus is on the road travelling with kids. But in a weekend it is parked. When a object stays still that means the the force which is working on the earth by the bus is equal to the force which works on the bus by the earth. we can understand it clearly by, Newton's second law of motion.
This pertains to the behavior of objects for which all existing forces are not balanced. The second law states that the acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object. so as it is when it is balanced it is not moving.
And on a school day the bus is moving so it has a force pulling itself forward . so it means that the force which the bus has is greater than the gravitational force.
The formula v=fλ can be used here.
326=2500*λ
Note the 2500 as 2.5kHz is 2.5 thousand Hz.
λ = 326/2500
= 0.1304m = 0.130m
