(adsbygoogle = window.adsbygoogle || []).push({}); (a) A snow sled with a child secured safely to it has a total mass of 56.0 kg. It is lowered at a constant speed of 1.1 m s−1 down a slope of angle 35.0 ° with respect to the horizontal (as shown above) for a distance d = 18.0 m. The coefficient of kinetic friction between the sled and the snow is 0.13.

Note: g = 9.8 m s–2. Air resistance is negligible at these speeds.

Find the magnitude of the reactive force, N, on the sled.

The correct answer should be 450.0 but my answer is different. I don't know how to solve this question but here's my attemp:

ΣFx = 1.1 cos 35.0° = 0.90

ΣFy = 1.1 sin 35.0 = 0.63

[tex]a = \frac{\sum F}{m}[/tex]

ax = 0.90 ÷ 56.0 = 0.01

ay = 0.63 ÷ 56.0 = 0.01

Now to find the magnitude:

[tex]\sqrt{0.01^2 + 0.01^2} = 0.01[/tex] "?"

≠ 450.0 N

Thanks.

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# Homework Help: Newton's 2nd & 3rd law

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