Urgent if earths gravitational field strength is 10 n/kg how many newtons does a 30kg object weigh

Determine the age of a fossil if it had only one eighth of its original carbon-14 content remaining?

What pressure difference is required between the ends of a 2.0-m-long, 1.0-mm-diameter horizontal tube for 40 c water to flow through it at an average speed of 4.0 m/s?

Which composition of water moves to begin a deepwater current?