Answer:
1373.4 N/m
Explanation:
Hooke's law states that the extension of a spring and force are related by the expression, F=kx where k is spring constant, x is extension of spring and F is the applied force. Making k the subject of the formula then

Also, F=gm hence the above formula is modified as

Taking g as 9.81 m/s2 , x as 0.5 m and m as 70 kg then

First, solve for the acceleration of the car. You know the mass of the car and the braking force, so you can use the equation Force = Mass x Acceleration. This gives you 12,000 = 2,000 x A. Divide 12,000 by 2,000 to find the acceleration equal to 6 m/s^2. This is the rate that the car is slowing down at. Velocity is equal to accleration x time (rate x time), so you multiply 6 by the time of 5 seconds. This leaves you with a velocity of 30 m/s or about 67.1 mph.
C.
Nitrogen has the atomic no. of 7 so the proton and the electron no. is 7.
Three more electrons are needed to fulfil the octet structure: 2,8
Answer:
Blue supergiants represent a slower burning phase in the death of a massive star. Due to core nuclear reactions being slightly slower, the star contracts and since very similar energy is coming from a much smaller area (photosphere) then the star's surface becomes much hotter.
Explanation:
I know this may not be the answer youre looking for, but hopefully this can help somehow!