{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Assign4

# Assign4 - PHY 53 Summer 2010 Assignment 4 Reading Dynamics...

This preview shows pages 1–2. Sign up to view the full content.

Assignment 4 Reading : Dynamics 2 Key concepts : Radial forces, effective gravity. 1. A block of mass m slides at constant speed down an incline of angle θ . a. What is the coefficient of kinetic friction μ k ? Ans : μ k = tan θ . b. The same block is sent up the incline, starting with speed v 0 . How far up the incline will it slide before coming momentarily to rest? Ans : v 0 2 2 g 1 sin θ + μ k cos θ . c. Will it slide back down by itself? Justify your answer. 2. Questions about a car rounding a curve of radius 216 m. Use g = 10 m/s 2 and ignore air effects. a. Suppose the curve is on level ground. How fast can a car go around it if μ s between tires and road is 0.6? Ans : 36 m/s . b. Suppose the curve is banked so a car at this speed does not need friction to round the curve. What is the banking angle θ ? Ans : tan θ = 0.6 . c. Now suppose there is rain on the banked curve, which reduces μ s to 0.3. What is the minimum speed a car must maintain on the curve to avoid sliding down the bank? Ans : 23.4 m/s . 3. A bucket is sliding to the right across a floor, and the level of the water in the bucket makes the angle shown with the horizontal. a. Is the bucket speeding up or slowing down? b. What is the magnitude of its acceleration, in terms of g and θ ? [What angle does the water surface make with g eff ?] Ans : a = g tan θ .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 4

Assign4 - PHY 53 Summer 2010 Assignment 4 Reading Dynamics...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online