Answer:

Explanation:
The torque is the force by the distance so to determinate that both torque are the same magnitude so




Solve to d2


If a scientist is studying a model that is a widely accepted theory about the position of planets and sun, the model would most likely help the scientist to understand facts that can't be easily observed. That will make the correct answer to be C.
Answer:
The maximum static frictional force is 40N.
Explanation:
When an object of mass M is on a surface with a coefficient of static friction μ, there is a minimum force that you need to apply to the object in order to "break" the coefficient of static friction and be able to move the object (Called the threshold of motion, once the object is moving we have a coefficient of kinetic friction, which is smaller than the one for static friction).
This coefficient defines the maximum static friction force that we can have.
So if we apply a small force and we start to increase it, the static frictional force will be equal to our force until it reaches its maximum, and then we can move the object and now we will have frictional force.
In this case, we know that we apply a force of 40N and the object just starts to move.
Then we can assume that we are just at the point of transition between static frictional force and kinetic frictional force (the threshold of motion), thus, 40 N is the maximum of the static frictional force.
Answer:
R = 1.8 m
Explanation:
This is a simple harmonic movement exercise, at the bottom of the swing the acceleration is vertical upwards and the speed is tangential to the trajectory, that is horizontal; the expression for the centralized acceleration is
= v² / R
R = v² /a_{c}
where the radius is equal to the length of the swing
let's calculate
R = 8.1 / 4.5
R = 1.8 m