Answer:

Explanation:
= normal force acting on the coin
Normal force in the upward direction balances the weight of the coin, hence

= frequency of rotation
Angular velocity of turntable is hence given as

= distance from the axis of rotation
= minimum coefficient of static friction
static frictional force is given as

The static frictional force provides the necessary centripetal force , hence
Centripetal force = Static frictional force

Answer:
1.95 kg
Explanation:
Momentum is conserved.
m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂
0 = (74.9) (-0.215) + m (8.25)
m = 1.95
Answer:
So the conclusion is that in presence of air net force acting downward reduces for feather and hence falls slower than coin. But in absence of air resistance, net downward force is just equal to force due to gravity which is same for both coin and feather and hence they fall down at the same rate.
1st derivative gives velocity;
d r(t)/ dt = 2t i + 6 j + 4/t k
2nd derivative gives acceleration;
d^2 r(t)/ dt^2 = 2 i - 4/ t^2
Speed ;
Square root of (4 t^2 + 36 + 16/ t^2)
For a given time, like 2 seconds, t will be 2. And answer of speed will be scalar.
The heat energy released from a piece of wire or any other section of a circuit is:
Energy = (voltage between its ends) x (current through it) x (time it's been going)