Exam_2_09s

# Exam_2_09s - Exam 2 Physics 130 Short Answer Section....

This preview shows pages 1–3. Sign up to view the full content.

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.

Unformatted text preview: Exam 2 Physics 130 Short Answer Section. Please answer all of the questions. 1. A 2000 kg automobile moves around an unbanked curve of radius 50 m at 30 m/s. What centripetal force is present due to friction. F c = mv 2 r = 2000 kg (30 m / s ) 2 50 m = 36,000 N 2. A 1500 kg elevator that is pulled by a single cable is accelerating downward at 0.2 m / s 2 . What is the tension in the cable? a = 0.2 m / s 2 ma = T mg T = ma + mg = 1500 kg ( 0.2 m / s 2 ) + 1500 kg (9.8 m / s 2 ) = 14, 400 N 3. A golf ball is hit from the ground with a velocity of 40m/s at an angle of 30 degrees. How long does it take to get to its maximum altitude and how far horizontally has it traveled when it reaches its maximum altitude. y i = m y f = ? v iy = 40sin 30 m / s = 20 m / s v fy = m / s a y = g t = ? v fy = v iy + a y t t = v fy v iy a y = 20 m / s 9.8 = 2.04 s x i = x f = ? v ix = 40cos 30 m / s = 34.6 m / s v fx = v ix a x = x f = x i + v ix t + 1 2 a x t 2 x f = + v ix t + = 70.67 m 4. A mass m slides down an incline at constant speed. The incline makes an angle with horizontal. Friction is present. What is the coefcient of friction? N = mg sin N = mg cos mg cos = mg sin = tan 5. A mass of 1000 kg is acted on by three forces: F 1 = 100 i + 250 j 350 k , F 2 = 50 i + 100 j 500 k and...
View Full Document

## This note was uploaded on 09/27/2010 for the course ASD 2456 taught by Professor Jojo during the Spring '10 term at Brooklyn Law School.

### Page1 / 10

Exam_2_09s - Exam 2 Physics 130 Short Answer Section....

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online