Suppose the block of the previous problem is pushed down the incline with a force of 4 N. How far will the block move in the first two seconds after starting from rest? The mass of the block is 4 kg.


Mass of the block m= 4kg

When no external force was applied, net force was given as


= mgsin30°-f


Here, external force F= 0.9m


Total net force along the inclination= mgsin30°-f+4 N


4× 9.8 × – (0.9 × 4)+ 4 N


= 20 N


Hence, the acceleration of the body a= ==5 m/s2


The distance travelled in time 2 secs after starting from rest is given by


s= ut + at2


= 10m


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