3. (a) Net force on a box with 10N and 5N forces is 15N. (b) Box moves upward due to the net force acting in the same direction.
4. (a) Net force on a textbook with opposing 20N forces is 0N. (b) Textbook remains stationary as opposing forces cancel out.
5. (a) Weight of a 60kg box is 588N (b) Bike with a weight of 400N has a mass of approximately 40.82kg.
3.
(a) The net force acting on the box is the sum of the individual forces:
Net Force = 10 N + 5 N = 15 N
(b) The box will move in the upward direction because the net force is acting in the same direction as the forces applied. Objects tend to accelerate in the direction of the net force.
4.
(a) The net force is the difference between the two forces:
Net Force = 20 N - 20 N = 0 N
(b) The textbook will not move because the net force is zero. When the forces acting on an object cancel each other out, there is no acceleration, and the object remains at rest or continues with constant velocity.
5.
(a) The weight (force of gravity) acting on the box is calculated using the formula:
Weight = mass × acceleration due to gravity
Weight = 60 kg × 9.8 m/s² = 588 N
(b) To find the mass of the bike, rearrange the formula:
mass = Weight / acceleration due to gravity
mass = 400 N / 9.8 m/s² ≈ 40.82 kg (rounded to two decimal places)
So, the weight of the box is 588 N, and the mass of the bike is approximately 40.82 kg.