Answer: 0.258 N
Explanation:
As the density of the object is much less than the density of water, it’s clear that the buoyant force, is greater than the weight of the object, which means that in normal conditions, it would float in water.
So, in order to get the ball submerged in water, we need to add a downward force, that add to the weight, in order to compensate the buoyant force, as follows:
F = Fb – Fg
Fb= δH20* 4/3*π*(d/2)³ * g
Fg = δb* 4/3*π*(d/2)³ *g
F= (δH20- δb) * 4/3*π*(d/2)³*g
Replacing by the values of the densities, and the ball diameter, we finally get:
F= 0.258 N
Answer:
Explanation:
Gravitational Potential Energy at earth surface 
Gravitational Potential Energy at height h is 
Energy required to lift the satellite 
Now Energy required to orbit around the earth
(given)
(b)For greater height 
is greater than 
thus energy to lift the satellite is more than orbiting around earth
Answer:
Option (e)
Explanation:
A = 45 cm^2 = 0.0045 m^2, d = 0.080 mm = 0.080 x 10^-3 m,
Energy density = 100 J/m
Let Q be the charge on the plates.
Energy density = 1/2 x ε0 x E^2
100 = 0.5 x 8.854 x 10^-12 x E^2
E = 4.75 x 10^6 V/m
V = E x d
V = 4.75 x 10^6 x 0.080 x 10^-3 = 380.22 V
C = ε0 A / d
C = 8.854 x 10^-12 x 45 x 10^-4 / (0.080 x 10^-3) = 4.98 x 10^-10 F
Q = C x V = 4.98 x 10^-10 x 380.22 = 1.9 x 10^-7 C
Q = 190 nC
Answer:
When the ejected air is moving in the downward direction then the thrust force acts in the upward direction, due to reversal thrust, the jets can take off vertically without needing a runway this way.
Explanation:
Newton’s third law motion states that for every action there will be an equal and opposite reaction.
Thrust reversal is also known as reverse thrust. It acts opposite to the motion of the aircraft by providing the deceleration.
Commercial aircraft moves the ejected air in the forward direction means that the thrust will acts opposite to the motion of the aircraft that is backward direction due to thrust reversal. This thrust force might be used to decelerate the craft.
Uses of thrust reversal in practice:
When the ejected air is moving forward direction then the thrust force moving backward direction due to reversal thrust the speed of the craft slows down.
When the ejected air is moving in the downward direction then the thrust force acts in the upward direction, due to reversal thrust, the jets can take off vertically without needing a runway this way.
