Author Question: A solid concrete wall 4.0 m by 2.4 m and 30 cm thick, with a thermal conductivity of 1.3 W/(mK), ... (Read 87 times)

karlynnae · **on:** Jul 29, 2018

A solid concrete wall 4.0 m by 2.4 m and 30 cm thick, with a thermal conductivity of 1.3 W/(mK), separates a basement at 18C from the ground outside at 6C. How much heat flows through the wall in one hour?

A)

1.8 MJ

B)

1.8 kJ

C)

500 J

D)

5.0 MJ

E)

5.0 kJ

Question 2

A solid sphere is rolling without slipping along a horizontal surface with a speed of 4.50 m/s when it starts up a ramp that makes an angle of 25.0 with the horizontal.

What is the speed of the sphere after it has rolled 3.00 m up the ramp?
A)

4.01 m/s

B)

8.02 m/s

C)

1.91 m/s

D)

2.16 m/s

E)

1.58 m/s