Question

1.

You have negotiated with the Omicronians for a base on the planet Omicron Persei 7. The architects working with you to plan the base need to know the acceleration of a freely falling object at the surface of the planet in order to adequately design the structures. The Omicronians have told you that the value is \(\mathrm{gOP7}=7.29 \frac{\text { flurg }}{\text { grom }^{2}}\), but your architects use the units \(\frac{\text { meter }}{\text { second }^{2}}\), and from your previous experience you know that both the Omicronians and your architects are terrible at unit conversion. Thus, it's up to you to do the unit conversion. Fortunately, you know the unit equality relationships: 5.24 flurg =1 meter and 1 grom =0.493 second. What is the value of \(g_{O P 7}\) in the units your architects will use, in \(\frac{\text { meter }}{\text { second }^{2}}\) ?

2.

 Solving Two Equations and Two Unknowns

 Two dimer signal dynamics often involves solving for two unknown quantities in two separate equations describing the total force. The block in has a mass m = 10 kg and is being pulled by a force F on a table with coefficient of static friction μ_s = 0.3. Four forces act on it:

 

 • The applied force F (directed θ = 30° above the horizontal).

 • The force of gravity F_g = mg (directly down, where g= 9.8 m/s²).

 • The normal force N (directly up).

 • The force of static friction f_s, (directly left. opposing any potential motion).

 

 If we want to find the size of the force necessary to just barely overcome static friction (in which case f_s = μ_sN).

 we use the condition that the sum of the forces in both directions must be 0. Using some basic trigonometry, we can

 write this condition out for the forces in both the horizontal and vertical directions, respectively, as:

 Fcosθ -μ_sN =0

 Fsinθ + N - mg =0

 In order to find the magnitude of force F, we have to solve a system of two equations with both F and the normal

 force N unknown. Use the methods we have learned to find an expression for F in terms of m, g, θ, and μ_s, (no N).

 F = _______ 

 Part G - Example: Finding Two Forces (Part II)

 For the situation in Part F, find the magnitude of the force F (in kg - m/s²) necessary to make the block move.

Answer 1