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2 years ago

A ball dropped from a bridge takes 3.0 seconds to reach the water below. How far is the bridge from the water?

1 answer:

8 0

Since it is dropped, initial velocity u = 0

Using s = ut + (1/2)gt^2, putting u = 0, g = 10 m/s^2

s =(1/2)gt^2, t = 3s

s = 0.5 * 10 * 3 *3

s = 45 m.

The bridge is 45m above the water.

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3 years ago

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2 years ago

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Neko [114]

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3 years ago

Ricardo, of mass 80 kg, and Carmelita, who is lighter, are enjoying Lake Merced at dusk in a 30 kg canoe. When the canoe is at r

Deffense [45]

Answer:

m=57.65 kg

Explanation:

Given Data

Ricardo mass m₁=80 kg

Canoe mass m₂=30 kg

Canoe Length L= 3 m

Canoe moves x=40 cm

When Canoe was at rest the net total torque is zero.

Let the center of mass is at x distance from the canoe center and it will be towards the Ricardo cause. So the toque around the center of mass is given as

$m_{1}(L/2-x)=m_{2}x+m_{2}(L/2-x)$

We have to find m₂.To find the value of m₂ first we need figure out the value of.As they changed their positions the center of mass moved to other side by distance 2x.

2x=40

x=40/2

x=20 cm

Substitute in the above equation we get

$m_{x}=\frac{m_{1}(L/2-x)-m_{2}x }{L/2+x}\\m_{x}=\frac{80(\frac{3}{2}-0.2 )-30*0.2}{3/2+0.2}\\m_{x}=57.65 kg$

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3 years ago