Asled is pushed with 30 newtons and sliding friction is 10 newtons find the net force on the sled

The net force is basically the speed or we could call it the centre of gravity. So it's simple:

to find the centre you minus the 2 numbers -

30 - 10 = 20

so the net force is 20

the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."

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