Answer:
William Gilbert
Explanation:
first described the Earth as a giant dipole magnet 400 years ago. But, as Rod Wilson recounts, he did far more than this.
Answer:
Final kinetic energy,
Explanation:
It is given that,
Kinetic energy of toy car, 
Frictional force, F = 0.5 N
Distance, d = 6 m
We need to find the kinetic energy after this frictional force has acted on it. We know that frictional force is an opposing force. The work done by the toy car is given by :


W = -3 J
We know that the work done is equal to the change in kinetic energy. Let
is the final kinetic energy.



So, the final kinetic energy is the toy car is 5 J. Hence, this is the required solution.
Answer:
5 ) The mass, 6) with lubrication and using surfaces that are not rough
Explanation:
5) If two bodies are held regardless of their densities and can be combined by some chemical or physical process, the only physical property to be modified will be the mass of the resulting body.
8)
Friction depends on the contact between two surfaces and when a body has a relative motion with respect to a contact surface. In order to reduce friction the contact surface must be lubricated, also the friction depends on the coefficient of friction between surfaces and the normal force exerted by the surface parallel to the area of contact with the body. Mathematically it can be expressed with the following equation.
![F_{f} = u*N\\where:\\u = friction coefficient\\N = normal force [Newtons]\\F_{f}= friction force [Newtons]](https://tex.z-dn.net/?f=F_%7Bf%7D%20%3D%20u%2AN%5C%5Cwhere%3A%5C%5Cu%20%3D%20friction%20coefficient%5C%5CN%20%3D%20normal%20force%20%5BNewtons%5D%5C%5CF_%7Bf%7D%3D%20friction%20force%20%5BNewtons%5D)