Question

A man pushes a 4kg block
with a force of 12N and
finds that it starts with an
acceleration of 2ms ? After
sometime, he finds that to
keep the block in motion
with uniform velocity 4 ms
1, he needs only a constant
force of 2N ifg=10ms?
find the coefficients of
static and dynamic
frictions​

Answer 1

Answer:

F- f = ma

where f = frictional force m is mass and a is acceleration

12- f= 4×2

f= 4N

f= fs× mg

4= fs×40

fs = 0.1

After sometime body is in uniform motion hence

a=0

f=F

f=2

2=fd×mg

2=fd×40

fd=0.05

Hope it will help you