To change from mass to weight is Fw = 30 kg * 9.8 m/s^2 = 294 N. To change from weight to mass divide by gravity (9.8 m/s^2).
I belive it could be 6.5 but I could be wrong
Answer: question 1 is b I believe
Explanation:
every action has an opposite reaction
Answer:
(a) 3.24 w (b) 44.44 ohm
Explanation:
It is given that car draws 0.27 A current so current I = 0.27 A
The system has a voltage of 12 V
(a) Electrical power = voltage ×current 
(b) The resistance is defined as the ratio of voltage and current
So resistance 
Answer:
3141N or 3.1 ×10³N to 2 significant figures. The can experiences this inward force on its outer surface.
Explanation:
The atmospheric pressure acts on the outer surface of the can. In order to calculate this inward force we need to know the total surface area of the can available to the air outside the can. Since the can is a cylinder with a total surface area given by 2πrh + 2πr² =
A = 2πr(r + h)
Where h = height of the can = 12cm
r = radius of the can = 6.5cm/2 = 3.25cm
r = diameter /2
A = 2π×3.25 ×(3.25 + 12) = 311.4cm² = 311.4 ×10-⁴ = 0.031m²
Atmospheric pressure, P = 101325Pa = 101325 N/m²
F = P × A
F = 101325 ×0.031.
F = 3141N. Or 3.1 ×10³ N.