Question

question 1: Let A be the last digit, let B be the second to last digit, and let C be the sum of the last three digits of your 8-digit student ID. Example: for 20245347, A = 7, B = 4, and C = 14.

Starting from rest, a student pulls a (25.0+A) kg box a distance of (4.50 + B) m across the floor using a (134 + C) N force applied at 35.0 degrees above horizontal. The coefficient of kinetic friction is 0.220 between the floor and the box. Find the work done by the pulling force. Give your answer in joules (J) and with 3 significant figures.

A=4 B=0 C=4

question 2:

Let A be the last digit, let B be the second to last digit, and let C be the sum of the last three digits of your 8-digit student ID. Example: for 20245347, A = 7, B = 4, and C = 14.

A (1.25+A) kg bowling ball is hung on a (2.50+B) m long rope. It is then pulled back until the rope makes an angle of (12.0+C) degrees with the vertical and released. Find the speed of the ball is at the lowest point. Give your answer in m/s and with 3 significant figures.

A= 4 B= 0 C= 4

question 3:

Let A be the sum of the last three digits, let B be the last digit, and let C be the second to last digit of your 8-digit student ID. Example: for 20245347, A = 14, B = 7, and C = 4.

Consider a cart with a mass of (2.40 + A) kg. Starting from rest the cart is pushed horizontally with a net force of (15.6 + B) N for a distance of (1.20 + C) m. Find the final kinetic energy of the cart. Give your answer in joules (J) and with 3 significant figures.

A= 4 B= 4 C= 0

question 4:

Let A be the last digit and let B be the sum of the last two digits of your 8-digit student ID. Example: for 20245347, A = 7 and B = 11.

A weight with a mass of (3.25+(A/10)) kg is hanging at rest on a spring with a spring constant of (262 + B) N/m. Determine the elastic potential energy of the spring at this point. Give your answer in joules (J) and with 3 significant figures.

A= 4 B= 4

Answer 1

work done by the pulling force

W = force * distance * cos

where is the angle between force direction and direction of motion

W = 148 * 8.5 * cos 35

W = 1030 J

___________________________

speed is maximum at lowest point

using conservation of energy

mgh = 1/2mv²

gh = 1/2v²

L ( 1 - cos ) g = 1/2v²

6.5 ( 1 - cos 26) 9.8 = 1/2 v²

so,

v = 3.59 m/s

_________________________________

work done = change in kinetic energy

initial K.E is zero,

so,

force * distance = K.E

22.6 * 5.2 = K.E

so,

K.E = 118 J

_____________________________

F = kx

x = F / k

x = mg / k

x = 3.95 * 9.8 / 273

x = 0.1417 m

so,

Energy = 1/2 * k * x²

Energy = 2.744 J