1. Two forces F~ 1 and F~
2 are acting on a block of mass m=1.5 kg. The magnitude of
force F~
1 is 12N and it makes an angle of θ = 37◦ with the horizontal as shown in
figure-1. The block is sliding at a constant velocity over a frictionless floor.
Figure-1
(a) Find the value of the normal force on the block.
[3 marks]
(b) Find the magnitude of force F~
2 that is acting on the block
[4 marks]
(c) Find the magnitude of force F~
2 if the block accelerates with a magnitude of
a = 2.5 m/s2 along the direction of F~
2 . [3 mark

(a) Normal force=7.48 N

Explanation:

N+F~1 sinθ-mg=0

=>N=1.5*9.8-12 sin37◦

=>N=14.7-7.22=7.48 N

which piece of furniture will have the most inertia and give the furniture movers the most difficulty in moving?  

answer

a 75kg dining table

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.