PHYS U1

Re < 1

Viscous, Fdrag = Fv

1 < Re < 1000

Mix of Viscous and Inertia

1000 < Re

Inertial drag

When a fluid is viscous, Fv = ?

Fdrag

1 um = ? m

10^-6 m

Can speed be negative?

No, speed = |v|

Can components be negative?

Yes

Can magnitudes be negative?

No

How do you find Ft btwn two blocks when one is pushed given Fpush?

1) Find the acceleration by treating everything involved as one object, Fnet = m X a , and since Fpush is the only force and we’re treating the 2 blocks as one system, Fnet = Fpush = masses of the two blocks X a

2) Find Ft on the block where it’s the only x force → Fnet^A= FT^A = m^A X (the acceleration you found in step 1)

In the equation for Fd, what units should pf be in?

Kg/m³

If a person is in an elevator, and the elevator starts accelerating upward, the what direction is the net force on the person?

Upward, Fnet is always in the same direction as the acceleration