I.i = j.j = 1
i.j = j.i = 0
(-2i - 5j)(i -4j)
= (-2i).i + (-2i).(-4j) + (-5j).i + (-5j).(-4j)
= -2 + 0 + 0 + 20 = 18
Answer:
a. 12.12°
b. 412.04 N
Explanation:
Along vertical axis, the equation can be written as
T_1 sin14 + T_2sinA = mg
T_2sinA = mg - T_1sin12.5 ....................... (a)
Along horizontal axis, the equation can be written as
T_2×cosA = T_1×cos12.5 ......................... (b)
(a)/(b) given us
Tan A = (mg - T_1sin12.5) / T_1 cos12.5
= (176 - 413sin12.5) / 413×cos12.5
A = 12.12 °
(b) T2 cosA = T1 cos12.5
T2 = 413cos12.5/cos12.12
= 412.04 N
Answer:
I. Speed = 20m/s
II. Velocity = 20m/s due North.
Explanation:
<u>Given the following data;</u>
Distance = 40m
Time = 2secs
To find the speed;
Mathematically, speed is given by the formula;

Substituting into the equation, we have;

<em>Speed = 20m/s.</em>
In physics, we use the same formula for calculating speed and velocity. The only difference is that speed is a scalar quantity and as such has magnitude but no direction while velocity is a vector quantity and as such it has both magnitude and direction.

<em>Therefore, the velocity is 20m/s due North</em>.
Answer:
Current = 0.063 Amperes
Explanation:
Let the three resistors be R1, R2, and R3 respectively.
Given the following data;
R1 = 25.0Ω,
R2 = 30.0Ω
R3 = 40.0Ω
Voltage = 6 Volts
First of all, we would determine the equivalent or total resistance;
Total resistance (in series) = R1 + R2 + R3
Total resistance = 25.0Ω + 30.0Ω + 40.0Ω
Total resistance = 95 Ω
Next, we find the current flowing through the circuit;
Voltage = current * resistance
Substituting into the formula, we have;
6 = current * 95
Current = 6/95
Current = 0.063 Amperes