6 Solutions 44918 1/26/09 1:45 PM Page 403

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600 N D
• 6–1. Determine the force in each member of the truss,
and state if the members are in tension or compression.

2m

900 N E
C

2m

A B

2m

403
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P1 P2
6–2. The truss, used to support a balcony, is subjected to
the loading shown. Approximate each joint as a pin and B
A C
determine the force in each member. State whether the
members are in tension or compression. Set P1 = 600 lb,
45° 45°
P2 = 400 lb.

4 ft

D 4 ft
4 ft

404
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
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P1 P2
6–3. The truss, used to support a balcony, is subjected to
the loading shown. Approximate each joint as a pin and B C
A
determine the force in each member. State whether the
members are in tension or compression. Set P1 = 800 lb,
45° 45°
P2 = 0.

4 ft

D 4 ft
4 ft

405
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*6–4. Determine the force in each member of the truss 2P

and state if the members are in tension or compression.
Assume each joint as a pin. Set P = 4 kN. P P

B C
A

4m
E

D
4m 4m

406
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
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• 6–5. Assume that each member of the truss is made of steel 2P

having a mass per length of 4 kg/m. Set P = 0, determine the
force in each member, and indicate if the members are in P P
tension or compression. Neglect the weight of the gusset plates
and assume each joint is a pin. Solve the problem by assuming B C
A
the weight of each member can be represented as a vertical
force, half of which is applied at the end of each member.
4m
E

D
4m 4m

407
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

6–6. Determine the force in each member of the truss and

state if the members are in tension or compression. Set A
P1 = 2 kN and P2 = 1.5 kN.

30° 30°
C
E D
3m 3m

P1 P2

408
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
publisher.

6–7. Determine the force in each member of the truss and

state if the members are in tension or compression. Set A
P1 = P2 = 4 kN.

30° 30°
C
E D
3m 3m

P1 P2

409
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

500 lb
*6–8. Determine the force in each member of the truss, 3 ft
3 ft 3 ft
and state if the members are in tension or compression. F E D
Set P = 800 lb.

3 ft

A
B C

410
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
publisher.

500 lb
• 6–9. Remove the 500-lb force and then determine the 3 ft
greatest force P that can be applied to the truss so that 3 ft 3 ft
F E D
none of the members are subjected to a force exceeding
either 800 lb in tension or 600 lb in compression.

3 ft

A
B C

411
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

4 ft 4 ft 4 ft 4 ft
6–10. Determine the force in each member of the truss P1
and state if the members are in tension or compression. Set
P1 = 800 lb, P2 = 0. C P2

B D 6 ft

E
A
G F

412
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
publisher.

4 ft 4 ft 4 ft 4 ft
6–11. Determine the force in each member of the truss P1
and state if the members are in tension or compression. Set
P2
P1 = 600 lb, P2 = 400 lb. C

B D 6 ft

E
A
G F

413
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*6–12. Determine the force in each member of the truss C D

and state if the members are in tension or compression. P1
Set P1 = 240 lb, P2 = 100 lb.
5 ft P2

A
B
12 ft

414
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publisher.

• 6–13. Determine the largest load P2 that can be applied C D

to the truss so that the force in any member does not exceed P1
500 lb (T) or 350 lb (C). Take P1 = 0.
5 ft P2

A
B
12 ft

415
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

1200 lb P 1200 lb
6–14. Determine the force in each member of the truss,
and state if the members are in tension or compression. Set

P = 2500 lb. 4 ft 4 4 ft 4 ft
E ft D C

4 ft

F G
30° 30°

A B

416
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
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1200 lb P 1200 lb
6–15. Remove the 1200-lb forces and determine the
greatest force P that can be applied to the truss so that
none

of the members are subjected to a force exceeding either 4 ft 4 4 4 ft

E ft ft C
2000 lb in tension or 1500 lb in compression.
D

4 ft

F G
30° 30°

A B

417
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

E
*6–16. Determine the force in each member of the truss,
and state if the members are in tension or compression. 1.5
Set P = 5 kN. m
D

1.5 m
C
A

1.5 m

P
B
2m 2m

418
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• 6–17. Determine the greatest force P that can be applied E

to the truss so that none of the members are subjected to a
force exceeding either 2.5 kN in tension or 2 kN in
1.5
compression.
m
D

1.5 m
C
A

1.5 m

P
B
2m 2m

419
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

900 lb
600 lb
6–18. Determine the force in each member of the truss,
and state if the members are in tension or compression. 4 4 ft 4 ft
ft
F E D

3 ft
C
A
B

420
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
publisher.

900 lb
6–19. The truss is fabricated using members having a 600
4 ft lb
weight of 10 lb> ft. Remove the external forces from the 4 4 ft
truss, and determine the force in each member due to the ft
weight of the members. State whether the members are in

tension or compression. Assume that the total force acting F E D

on a joint is the sum of half of the weight of every
member connected to the joint. 3 ft
C
A
B

421
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

422
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
publisher.

*6–20. Determine the force in each member of the truss 0.1

and state if the members are in tension or compression. m
The load has a mass of 40 kg.
D
E
3.5 m
F
C

G
B

2.5 m

A
6m

423
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

0.1
• 6–21. Determine the largest mass m of the suspended
m
block so that the force in any member does not exceed
30 kN (T) or 25 kN (C).
D
E
3.5 m
F
C

G
B

2.5 m

A
6m

424
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
publisher.

6–22. Determine the force in each member of the truss, 400 N

600 N
and state if the members are in tension or compression.

E D

45° 45 45°
A
° 45°
B C

2m
2m

425
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

600 N
6–23. The truss is fabricated using uniform members 400
N
having a mass of 5 kg> m. Remove the external forces
from the truss, and determine the force in each member D
due to the weight of the truss. State whether the members E
are in tension or compression. Assume that the total force
acting on a joint is the sum of half of the weight of every
member

connected to the joint. 45° 45 45° 45°

A C
°
B

2m 2m

426
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
publisher.

*6–24. Determine the force in each member of the truss,

3m 3m 3m
and state if the members are in tension or compression. F E
Set P = 4 kN.
3m
A B C D

P P

427
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

3m 3m 3m
• 6–25. Determine the greatest force P that can be applied F E
to the truss so that none of the members are subjected to a

force exceeding either 1.5 kN in tension or 1 kN in 3m

compression. A B C D

P P

428
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
publisher.

6–26. A sign is subjected to a wind loading that exerts 300 lb

C
horizontal forces of 300 lb on joints B and C of one of the
side supporting trusses. Determine the force in each
member of the truss and state if the members are in 12 ft
tension or compression. 13
ft
D

5 ft

300 lb
B 12 ft

13
45° ft E
A

429
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B C
6–27. Determine the force in each member of the double
scissors truss in terms of the load P and state if the members
are in tension or compression. L/3

E F D
A

L/3
L/3 L/3

P P

430
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
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*6–28. Determine the force in each member of the truss in P B

terms of the load P, and indicate whether the members are
in tension or compression.
d

A C
F D

d d/2 d/2 d

431
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

•6–29. If the maximum force that any member can support P B

is 4 kN in tension and 3 kN in compression, determine the
maximum force P that can be applied at joint B. Take
d = 1 m. d

A C
F D

d d/2 d/2 d

432
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currently exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the
publisher.

6–30. The two-member truss is subjected to the force of

B
300 lb. Determine the range of u for application of the load so
that the force in either member does not exceed 400 lb (T)
or 200 lb (C).

3 ft

A C

u 4 ft

300
lb

433
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exist. No portion of this material may be reproduced, in any form or by any means, without permission in writing from the publisher.

434
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