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:
4 times
Explanation:
As we know that the energy of a wave is directly proportional to the square of the amplitude of the wave,
Here, the amplitude of the wave A is twice as compared to B.
So, the energy of wave A is 4 times the energy of wave B.
As we know the formula of kinetic energy is
here given that
KE = 150,000 J
mass = 120 kg
we can use this to find speed
So speed of above object is 50 m/s
the magnitude of charge=q=8.76 x 10⁻⁵C
Explanation:
the magnetic force Fm is given by
Fm= q V B sinθ
q= charge
v= velocity= 2.5 x 10⁴ m/s
B= magnetic field strength= 8.1 x 10⁻²T
Fm= magnetic force= 7.5 x 10⁻² N
θ=25°
so 7.5 x 10⁻² =q (2.5 x 10⁴ ) (8.1 x 10⁻²) sin25
q=8.76 x 10⁻⁵C
