The figure shows two 1.0 kg-blocks connected by a rope. A second rope hangs beneath the lower block. Both ropes have a mass of 250 g. The entire assembly is accelerated upward at 2.3 m/s2 by force . What is the tension at the top end of rope 1?
A) 18 N
B) 15 N
C) 2.9 N
D) 3.5 N
Answer: A
You might also like to view...
This graph plots planetary mass on the horizontal axis and planetary radius on the vertical axis. Which of the four points marked by one of the bold numbers 1 through 4 represents a planet that has about the same composition as Earth but is larger in both size and mass?
A) Point 1 B) Point 2 C) Point 3 D) Point 4
This design involves only one optical surface, a concave mirror
A) prime focus reflector B) Newtonian reflector C) Cassegrain reflector D) Gregorian reflector E) refractor
A high-speed computer is located in a temperature controlled room of 26°C. When the machine is operating its internal heat generation rate is estimated to be 800 W. The external surface temperature is to be maintained below 85°C. The heat transfer coefficient for the surface of the computer is estimated to be 10 W/(m2 K). What surface area would be necessary to assure safe operation of this machine? Comment on ways to reduce this area.
GIVEN
• A high-speed computer in a temperature controlled room
• Temperature of the room (T?) = 26°C
• Maximum surface temperature of the computer (Tc) = 85°C
• Heat transfer coefficient (U) = 10 W/(m K)
• Internal heat generation q
G= 800 W
FIND
• The surface area (A) required and comment on ways to reduce this area
ASSUMPTIONS
• The system is in steady state
SKETCH
A steel wire, 86.0 m long at 21°C, has a coefficient of linear expansion of 11 × 10^?6/C°. Give its change in length as the temperature changes from 21°C to 36°C
a. 2.0 cm b. 3.4 cm c. 1.4 cm d. 0.21 cm e. 6.3 cm