Question

The figure below shows a diver of weight 800 N standing at the end of a diving board with a length L = 4.1 m and negligible mass. The board is fixed to two pedestals (supports) separated by distance d = 1.5 m.

-7- ka/

(a) Of the forces acting on the board, what is the magnitude of the force from the left pedestal?
____ N

(b) Of the forces acting on the board, what is the direction of the force from the left pedestal?

Choices:

1) up

2) down

(c) Of the forces acting on the board, what is the magnitude of the force from the right pedestal?
___ N

(d) Of the forces acting on the board, what is the direction of the force from the right pedestal?

Choices:

1) up

2) down    

(e) Which pedestal is being stretched?

Choices:

1) The left pedestal is being stretched.

2)The right pedestal is being stretched.    

(f) Which pedestal is being compressed?

Choices:

1) The left pedestal is being compressed.

2) The right pedestal is being compressed.   

Answer 1

Soch K Given, NB 80ON L24.1m Kd A dalism B (2) Stuce the system is an equilibrium, ". Net external torque about Bro Die Binet 0 NA-d - 800x (L-d) 20 800 (4.1-1.5) » NA ie, NA=1386.67N (6) Stale NA Comes out to be positive, the direction of NA shown in the figure as correct, le, the direction of the force from the left pedestal is an downward direction. Hence option (2) is correct. C Net torque about Aro tę net no No d - 8000l 20 800 x 4.1 vre NB2 2186.67 N (d) Stuce No is positive, hence direction shown in the figure as comect. So, the direction of force from the right pedestal is an upward direction, Hence, option (1) is correct.

FBD of pedestals is given as~ ANA INA => A INB NA (e) The left pedestal is stretched. Hence, option (1) is correct. (f) the right pedestal as Compressed. Hence, option (2) es correct.