Question

Andy and Bob are carrying Chuck on a horizontal board 4.8 meters long which weighs 18 N. Chuck's mass is 70 kg and he sits 0.3 meters from Andy. The force that Andy exerts upwards is ______ N.

Answer 1

Answer on question #69296, Physics / Other

Question Andy and Bob are carrying Chuck on a horizontal board 4.8 meters long which weighs 18 N. Chuck's mass is 70 kg and he sits 0.3 meters from Andy. The force that Andy exerts upwards is ? N.

Solution Force from board is 9 N, as it uniformly acts on Andy and Bob. The force from Chuck is inversely proportional to distance:

$$\frac {F _ {a}}{F _ {b}} = \frac {d _ {b}}{d _ {a}}$$ $$F _ {a} + F _ {b} = m g = 7 0 \cdot 9. 8 = 6 8 6 N$$

From this we find

$$F _ {a} = 6 4 3. 1 2 5 N$$

Hence, Andy exerts upwards

$$9 + 6 4 3. 1 2 5 = 6 5 2. 1 2 5 N$$