Anet force of 15 n is exerted on an encyclopedia to cause it to accelerate at a rate of 5 m/s². determine the mass of the encyclopedia

The first week samantha learned to read braille, she could read 10 words per minute. in the second week she increased her speed by 20%. in the third week she increased her speed again by another 25%. how many words could she read per minute by the third week? hurry and tell me!