P = IV
I = P/V = 30 / 120 = 0.25 A.
Current = 0.25A
Answer:

West
Explanation:
m = Mass of car = 
t = Time = 9 seconds
u = Initial velocity = 30 m/s
v = Final velocity = 0
Impulse is given by

The magnitude of the total impulse applied to the car to bring it to rest is
.
The direction is towards west as the sign is negative.
Answer:
Explanation:
Given that,
Force is downward I.e negative y-axis
F = -2 × 10^-14 •j N
Magnetic field is westward, +x direction
B = 8.3 × 10^-2 •i T
Charge of an electron
q = 1.6 × 10^-19C
Velocity and it direction?
Force in a magnetic field is given as
F = q(V×B)
Angle between V and B is 270, check attachment
The cross product of velocity and magnetic field
F =qVB•Sin270
2 × 10^-14 = 1.6 × 10^-19 × V × 8.3 × 10^-2
Then,
v = 2 × 10^-14 / (1.6 × 10^-19 × 8.3 × 10^-2)
v = 1.51 × 10^6 m/s
Direction of the force
Let x be the direction of v
-F•j = v•x × B•i
From cross product
We know that
i×j = k, j×i = -k
j×k =i, k×j = -i
k×i = j, i×k = -j OR -k×i = -j
Comparing -k×i = -j to given problem
We notice that
-F•j = q ( -V•k × B×i)
So, the direction of V is negative z- direction
V = -1.51 × 10^6 •k m/s
The complete cycle of phases lasts 29.531 days.
From New Moon to Full Moon is half of that . . . 14.765 days,
which is very close to 2 weeks.
Answer:

Explanation:
<u>Density
</u>
The density of a substance is the mass per unit volume. The density varies with temperature and pressure.
The formula to calculate the density of a substance of mass (m) and volume (V) is:

We have a cube-shaped piece of copper of 4 cm of side length. The volume of the piece is:

Surprisingly, no other magnitude is required, thus the answer is:
