# reaction at point A of the thin planel on a decelerating truck

In problem 16.3(a), A 60-lb uniform thin panel is placed in a truck with end A resting on a rough hoirzontal surface and end B supported by a smooth vertical surface. Knowing that the deceleration of the truck is 12 ft/s^2, determine the reactions at ends A is

a. 70.03 lb

b. 60.30 lb

c. 90.70 lb

d. 80.71 lb

https://brainmass.com/physics/gravity/reaction-at-point-a-of-the-thin-planel-on-a-decelerating-truck-108767

#### Solution Preview

Let g = 9.8 m/s^2 be the free fall acceleration

Let m = (80 lb / g) be the mass of the track

a = -10 ft/s^2 = - 3.048 m/s^2 the acceleration of the truck (negative because it decelerates)

B = 30 degrees = the angle between the vertical and the panel

Let L be the length of the panel, so that the height of point B is

hb = Lcos(B) (1)

and the length of the horizontal projection of the panel is

wb = Lsin(B). (2)

We shall use these sizes for calculating the torques below.

The ...

#### Solution Summary

It shows how to find the reaction force at point A of the thin planel on a decelerating truck.