Agirl and her dog sit on a seesaw. the dog has mass of 20.0 kg and sits 1.5 m from the pivot point and the girl has mass of 65.0 kg. in order to balance the seesaw, the girl should sit at a distance of : (a) 0.5 m (b) 0.64 m (c) 0.46 m (d) 6.04 m

(c) d₂ = 0.46 m

Explanation:

We apply Newton's first law to balance moments (M) at the point O at the bottom of the ladder, taking positive the moments that go counterclockwise and negative the moments that go clockwise

ΣMo=0

W₁*d₁ - W₂*d₂ = 0 Equation (1)

W₁ = dog Weight (N)

W₂= girl Weight (N)

d₁ = distance from W₁ to point O

d₂ = distance from W₂ to point O

Data

m₁ =  20.0 kg : dog mass

m₂ = 65.0 kg : girl mass

g = 9.8 m/s² : acceleration due to gravity

d₁ = 1.5 m

We calculate W₁ and W₂ :

W₁=m₁*g=  20.0 kg*9.8 m/s  = 196 N

W₂=m₂*g=  65.0 kg*9.8 m/s  = 637 N

Look at the free body diagram of the seesaw in the attached graphic

In the equation (1):

W₁*d₁ - W₂*d₂ = 0

196*(1.5) - 637*(d₂) = 0

294 = 637*(d₂)

d₂ = 294/637

d₂ = 0.46 m

the answer would be c

the moon affects the earth gravitation ally, causing certain motions of that body and also producing tides in its ocean and atmosphere. the tidal wave in our atmosphere is, however, far too minute to be an effective cause in any known meteorological phenomenon.

explanation: