Asteady force of friction acts on a 15.0-kg mass moving initially at 10.0 m/s on a horizontal surface. show that if the mass is brought to rest over a distance of 12.5 m the friction force is 60 n

As we know that block is moving at speed 10 m/s and comes to rest after travelling 12.5 m distance

so here we will have

now we know that

here we have

m = 15 kg

a = -4 m/s^2

so we will have

F = 15(4) = 60 N

so friction force on it will be 60 N