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I will be so thankful if u answer correctly!!​

I will be so thankful if u answer correctly!!​-example-1
User Krzaq
by
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1 Answer

3 votes

Answer:

(a) 10N

Step-by-step explanation:

The sketch of the two cases has been attached to this response.

Case 1: The box is pushed by a horizontal force F making it to move with constant velocity.

In this case, a frictional force
F_(r) is opposing the movement of the box. As shown in the diagram, it can be deduced from Newton's law of motion that;

∑F = ma -------------------(i)

Where;

∑F = effective force acting on the object (box)

m = mass of the object

a = acceleration of the object

∑F = F -
F_(r)

m = 50kg

a = 0 [At constant velocity, acceleration is zero]

Substitute these values into equation (i) as follows;

F -
F_(r) = m x a

F -
F_(r) = 50 x 0

F -
F_(r) = 0

F =
F_(r) -------------------(ii)

Case 2: The box is pushed by a horizontal force 1.5F making it to move with a constant velocity of 0.1m/s²

In this case, the same frictional force
F_(r) is opposing the movement of the box.

∑F = 1.5F -
F_(r)

m = 50kg

a = 0.1m/s²

Substitute these values into equation (i) as follows;

1.5F -
F_(r) = m x a

1.5F -
F_(r) = 50 x 0.1

1.5F -
F_(r) = 5 ---------------------(iii)

Substitute
F_(r) = F from equation (ii) into equation (iii) as follows;

1.5F - F = 5

0.5F = 5

F = 5 / 0.5

F = 10N

Therefore, the value of F is 10N

I will be so thankful if u answer correctly!!​-example-1
User Panfeng Li
by
3.7k points