Abox (m = 20 kg) is sliding on a horizontal surface. it is connected to a massless hook by a light string passing over a massless pulley wheel. the coefficients of friction between the box and the surface are 0.80 (static) and 0.30 (kinetic). if 15 kg (in total) are placed on the hook, calculate the acceleration of the box.

mass of the box = 20 kg

force of friction on the box due to surface

similarly kinetic friction on it

now the weight of the suspended block will be

so here the weight of the suspended block is less than the limiting friction on it

So here we will say that friction will counter balance the weight of the suspended block and it will not move at all

So acceleration of the box will be zero

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.

1.195000

explanation:

total mass=0.0117+0.0137+0.0881+0.0111

total mass= 0.01172kg

total velocity = 0.283-0.743+0.871-0.799+0.155+0.637+0.301=0.102

momentum=mv=0.1172*0.102=1.195000//