A tennis ball (m=0.2 kg) is thrown at a brick wall. it is traveling horizontally at 18 m/s just before hitting the wall and rebounds the wall at 12 m/s, still traveling horizontally. the ball is in contact with the wall for 0.02 s. what is the magnitude of the average force of the wall on the ball

Year  1936,  lehman predicted that the earths 'inner core' is solid. she observed that the seismic signals during her study were bent and did not pass through instead bouncing back. later it was confirmed that the earth's inner core was solid made up of nickel-iron and had a molten outer core.

Chope i i hope i did

Let  be the velocity of the plane.let  be the velocity of the wind.let  be the resultant velocity.add the velocities to find the resultant velocity. in the attached picture, i have done the tail-to-tip method: draw one of the vectors, then add the end of the other vector to the tip of the first drawn vector.see diagram.the magnitude of  can be found via the pythagorean theorem as this is a right angle triangle.to find  , use inverse tangent: since  is in the direction "east of north", a quick convert to "north of east " reveals that 90 - 7.06 = 82.94 = 83.so our resultant is 529 m/s [83° n of e]the answer is a.