A block of mass 6kg is placed on a horizontal floor. when it is pulled by a force of 30N, it moves with a constant speed of 15 m/s.?
(a) calculate the resultant force?
(b) calculate the frictional force?
(c) the block is now pulled with a force of 35N for 3s calculate
(i) the acceleration?
(ii) the speed of the block after 3s?
- sojsailLv 77 years agoFavorite Answer
Ooops, I didn't see question c till submiting a and b. Pretend this is at the bottom.
c. Fres was 0 when applied force was 30. So now Fres=5N.
i. Fres = mass*acceleration
Solve for accel.
ii. Use the kinematic formula
Vf = Vi + a*t
where Vi is initial velocity = 0, a is accel, and t is 3 s.
I started here.
Constant speed, so acceleration is zero.
Fres = mass * acceleration
That is Newton's 2nd law
Fres = 6 kg * 0 = 0
Fres is the resultant of forces on the block.
Fres = applied force + friction
You know from above that Fres is zero and applied force is given as 30N. Plug 'em in and solve for friction.