It can be found in granitic and basaltic rock.
It's angle of reflection must be 41 degrees
we know, by the first law of reflection that angle of incidence is always equal to angle of reflection..........
Since force is mass*acceleration,
F = 70kg * 9.8 m/s
It would be kinetic energy. Let's say the book is weighs 10 Newtons you need to use a force of 10 Newtons to lift the book. In other words it's positive. As you move the book you're giving it energy. Namely potential energy which will turn to kinetic energy if you let it go. So you're changing it's position and energy.
