A man is 40 kg . calculate his weight.(g=10m/s^2)

The image shows the positions of a car on a roller coaster track. arrange the cars in order based on their gravitational potential energy. begin with the lowest potential energy and end with the highest.

Which of the following changes will result in a stronger electromagnet? a. using fewer coils of wire b. using a higher voltage c. using a shorter nail d. using a longer wire

Give one example to show that when substances are mixed, it may result in a chemical or a physical change depending on the conditions.