Answer:
56250 N
Explanation:
mass, m = 6000 kg
initial speed, u = 20 m/s
final speed, v = 5 m/s
distance, s = 20 m
Use third equation of motion

5 x 5 = 20 x 20 + 2 a x 20
25 = 400 + 40 a
a = - 9.375 m/s^2
Braking force, F = mass x acceleration
F = 6000 x 9.375
F = 56250 N
Answer:
The magnitude of the net force is 5430N
Explanation:
I suggest to define the axes as aligned to the axis of the plane. This will require you to decompose only one vector, namely the Weight. We need two components of the W force: one in horizontal direction of the plane, the other perpendicular to it. Through a simple triangle argument you will se that the plane-horizontal component of W is

acting in the direction of the Drag, and the plane-perpendicular component is:

with negative sign since it counteracts the Lift.
So the components of the netforce F are:

The magnitude of the net force is:

'A' and 'C' are exactly the same circuit, except the voltmeter's terminals are flipped.
'A' is the correct way to hook everything up.
If you start at the positive terminal of the battery, and follow the flow of current through the circuit and around to the negative terminal, you're following the path where the voltage gets lower and lower and lower all the way.
So each time you come to any device in the circuit ... whether it's a resistor or a meter ... you would be hitting the positive side of it first, and then the voltage where you come out on the other side of it would be lower.
So the left side of the resistor is more positive, and the right side is more negative. The voltmeter is connected correctly in 'A', but it's backwards in 'C'. If you connect the voltmeter like in 'C' and turn things on, the voltmeter will try to go <em>down</em> from zero. You can't read the number on it, and It's possible that the voltmeter might be damaged.