1. • Here, force of gravity on the block = 20 N.
• Therefore, the normal force will also be the same, i.e., 20 N [According to Newton's Third Law, on every action, there is an equal and opposite reaction]
• The coefficient
[tex] u_{k} = 0.4[/tex]
• Force of friction =
[tex]u_{k} \times \: normal \: \: \: force \\ = 0.4 \times 20N \\ = 8N[/tex]
• Hence, the force of sliding friction between the block and the ground is 8 N.
• So, it is option c. 8 N
2. The answer is option d. continue in the same direction with no change in speed.
We know, force = mass × acceleration. When force is 0, then acceleration will also be 0 since mass cannot be 0. So, there will be no change in speed.
3. It is option b. force that is required to give a one kilogram object the acceleration of 1 m/s^2.
Newton is the SI unit of force. As mentioned earlier, force = mass × acceleration. The SI unit of mass and acceleration is Kg and m/s^2 respectively.
So, 1 N = 1 Kg × 1 m/s^2.
4. It is d. not zero.
Acceleration is the change in speed. So, if the force is zero, then acceleration will not occur.
5. Force = 2 N
Acceleration of the object A = 2 m/s^2.
Acceleration of the object B = 1 m/s^2.
Therefore, mass of the object A = 2 N ÷ 2 m/s^2 = 1 Kg
And, mass of the object B = 2 N ÷ 1 m/s^2 = 2 Kg
So, the mass of object B is greater than that of object A.
Hence, the answer is option c. Object B has more mass.
Hope you could get an idea from here.
Doubt clarification - use comment section.
