Answer:
Explanation:
We shall apply concept of impulse
Impulse = Force x time
= Force x 2 x 10⁻³ N.s
impulse = change in momentum
change in momentum
= .4 x 4 - ( - .4 x 2 )
= 2.4
Force x 2 x 10⁻³ = 2.4
Force = 2.4 / 2 x 10⁻³
= 1.2 x 10³ N .
average magnitude of the force exerted by floor = 1.2 x 10³ N
If R be reaction force by earth
R - mg = 1.2 x 10³
R = 1.2 x 10³ + mg
= 1200 + .4 x 9.8
= 1200 +3.92
= 1203 .92 N .
Answer:
They create electricity from the sun's rays
Explanation:
By the use of "solar cells" or "solar panel", you can trap solar energy in silicon/germanium rods, then you can convert in into electricity too. Solar powered panels convert the sun's rays into electricity by exciting electrons in silicon cells using the photons of light from the sun. This electricity can then be used to supply renewable energy to your home or business.
Answer:
Utilization, effects
Explanation:
The conductors that carry the current to electrical devices and utilization equipment are the heart of all electrical systems. There are associated effects whenever current flows through a conductor.
Answer:
The angle formed of the rope with the surface = 40°
Force applied = 125Newtons
The displacement covered by the box =25metres
W= FDcos theta
[125×40×cos(40°) ] Joules
= [ (3125×0.76604444311)]Joules
= 2393.88888472 joules(ans)
Hope it helps
Answer:
false statement : b ) For the motion of a cart on an incline plane having a coefficient of kinetic friction of 0.5, the magnitude of the change in kinetic energy equals the magnitude of the change in gravitational potential energy
Explanation:
mechanical energy = potential energy + kinetic energy = constant
differentiating both side
Δ potential energy + Δ kinetic energy = 0
Δ potential energy = - Δ kinetic energy
first statement is true.
Friction is a non conservative force so inter-conversion of potential and kinetic energy is not possible in that case. In case of second option, the correct relation is as follows
change in gravitational potential energy = change in kinetic energy + work done against friction .
So given 2 nd option is incorrect.
In case of no change in gravitational energy , work done is equal to
change in kinetic energy.
