Pulleys can be used to lift heavy objects that otherwise may not be able to be lifted. They reduce the amount of force it takes to lift a load.
When you push on a wall, the wall pushes back on you with a force equal in strength to the force you exerted.
Answer:
Explanation:
For resistance of a wire , the formula is as follows .
R = ρ L/S
where ρ is specific resistance , L is length and S is cross sectional area of wire .
for first wire resistance
R₁ = ρ 3L/3a = ρ L/a
for second wire , resistance
R₂ = ρ 3L/6a
= .5 ρ L/a
For 3 rd wire resistance
R₃ = ρ 6L/3a
= 2ρ L/a
For fourth wire , resistance
R₄ = ρ 6L/6a
= ρ L/a
So the smallest resistance is of second wire .
Its resistance is .5 ρ L/a
Answer:
Part a)
Part b)
Part c)
F = 2.7 N
Explanation:
Part a)
As we know that the rotational kinetic energy of the merry go round is given as
here we know that
Now we have
Part b)
Now we know that work done due to torque = change in kinetic energy
Part c)
In order to stop it in four revolutions we have
F = 2.7 N
Answer:
A:The dissaperance of a solid stirred in water