Encrypting your link and protect the link from viruses, malware, thief, etc! Made your link safe to visit.

 

Question:


Suppose two children are using a uniform seesaw that is 3.00 m long and pivoted at 2 m from the left edge, and a 30.0 kg child sits 1.40 m to the right  of the the center of mass of the seesaw. Seesaw weighs 5 kg.

a. Calculate where the second 18.0 kg child must sit to balance the seesaw. [ 5 points]

b. How far will the child be from the center of mass of the seesaw? [ 2 points]

c. How far will the child be from the left edge of the seesaw? [3 points] 


Answer:


(a)

Length of seesaw l = 3 m

Pivot point is at 2m from left

Centre of mass of seesaw is at 1.5 m, therefore, distance of centre of mass from pivot point is

lc = 2 - 1.5 m =0.5m

The child sits 1.40 m to the right of the the center of mass of the seesaw. So, distance of child from pivot point is

lR = 1.40 - 0.5 m = 0.9 m, towards right

mass of child at right mR = 30kg

mass of seesaw,mc= 5 kg

mass of child at left, mL = 18 kg

distance of left child from pivot point = lL

Child on the left and centre of mass of seesaw provide a anticlockwise torque whereas student on the right provide a clockwise torque.

For rotational symmetry

ml + mclc = mRlR

18 * 1 + 5*0.5 = 30 * 0.9

18 *lL + 2.5 = 27

1.36т                                                           (Ans)

The child should sit at 1.36 m from the pivot point, towards left

 

(b)

The center of mass of the seesaw is at 0.5m from the pivot

Distance of child to the centre of mass is

dlc = 1.36m - 0.5m = 0.86m                    (Ans)

 

(c)

The distance of left edge to the pivot point is 2m

Distance of child from the left edge is

di = 2m – 1.36m = 0.64m                    (Ans)

ST

Search This Blog

Labels

Report Abuse

A palindrome is a number or a text phrase that reads the same backwards as forwards. For example, each of the following five-digit integers is a palindrome: 12321, 55555, 45554 and 11611. Write a C++ program that reads in a five-digit integer and determines whether it is a palindrome .

Question: A palindrome is a number or a text phrase that reads the same backwards as forwards. For example, each of the following five-digit integers is a palindrome: 12321, 55555, 45554 and 11611. Write a C++ program that reads in a five-digit integer and determines whether it is a palindrome . Answer: Step 1 PROGRAMING CODE:   #include <stdio.h> int main() {   int n, a, b, c, d, e;   int digit = 0;   printf( "Enter one 5 digit number: \n" );   scanf( "%d", &n );   a = n / 10000;   b = n / 1000 % 10;   c = n / 100 % 10;   d = n / 10 % 10;   e = n % 10;   if ( a == e && b == d ) {     printf( "Palindrome!\n" );   }   if ( a != e || b != d ) {     printf( "Not a palindrome.. :(\n" );   }   return 0; } PROGRAM SCREENSHOT: Step 2

QUESTION 6 (a) The bar shown in Figure Q2(a) is subjected to tensile load of 150 Kn. If the stress in the middle portions is limited to 160 N/mm², determine the diameter of the middle portion. Find also the length of the middle portion if the total elongation of the bar is to be 0.25 mm. E E = 2.0 + 105N/mm². (12 marks) 150 KN 10 cm DIA 10 cm DIA 150 KN 45 cm Figure Q6(a) (b) A brass bar, having cross-section area of 900 mm², is subjected to axial forces as shown in Figure Q2(b), in which AB = 0.6 m, BC = 0.8 m, and CD = 1.0 m. Find the total elongation of the bar. E = 1.0 + 105N/mm2 . (8 marks) Page 4 of 5 B D 40 KN 70 KN 20 KN 10 KN Figure Q6(b) (TOTAL = 20 MARKS)

  Question: Show transcribed image text Answer:

Contributors