Answer:
A kilowatt (kW) is a unit of power.
Explanation:
The power of an object is given by :
Here,
E is the energy required
t is time
The SI unit of power is Watts and the SI unit of energy is Joule. the commercial unit of energy is kilowatt per hour.
Option (1) : A kilojoule (kJ) is a unit of power is incorrect.
Option (2) : A gigawatt (GW) is a unit of energy is incorrect.
Option (3) : A watt (W) is a unit of energy is incorrect.
Option (4) : A kilowatt x hour per year (kWh/yr) is a unit of energy is incorrect.
Option (4) : A kilowatt (kW) is a unit of power is correct.
Hence, the correct option is (d).
Answer:
323 m/s²
Explanation:
Given:
x₀ = 0 m
y₀ = 0 m
x = 29500 cos 65°
y = 29500 sin 65°
v₀x = 1810 cos 20°
v₀y = 1810 sin 20°
t = 9.20
Find:
ax, ay, θ
First, in the x direction:
x = x₀ + v₀ t + ½ at²
29500 cos 32° = 0 + (1810 cos 20°) (9.20) + ½ ax (9.20)²
25017 = 15648 + 42.32 ax
ax ≈ 221.4
And in the y direction:
y = y₀ + v₀ t + ½ at²
29500 sin 32° = 0 + (1810 sin 20°) (9.20) + ½ ay (9.20)²
15633 = 5695 + 42.32 ay
ay ≈ 234.8
Therefore, the magnitude of the acceleration is:
a² = ax² + ay²
a² = (221.4)² + (234.8)²
a ≈ 322.7
Rounded to 3 significant figures, the magnitude of the acceleration is approximately 323 m/s².
Answer:
-0.105 m/s
Explanation:
Given that
Mass of the astronaut, m(a) = 68.5 kg
Mass of the tool, m(t) = 2.25 kg
Speed of the tool after it is thrown, v(t) = 3.20 m/s
We know that momentum of a particle,
p = mv
See the attachment for calculations
Therefore, the speed is 0.105 m/s and it moves in the opposite direction.
Answer:
2.25 N upwards
Explanation:
Answer:
800 N/C to the right
Explanation:
The equation that relates force on a charge, electric field and charge is
where
F is the force acting on the charge
q is the charge
E is the electric field
In this problem, we have
is the electric field
is the charge
Substituting into the formula, we find the force
Concerning the direction:
- The electric field and the force have same directions if the charge is positive
- The electric field and the force have opposite directions if the charge is negative
Here the charge is negative, so the electric field has opposite direction to the force: therefore, it must be upwards.
Explanation:
Spring tides generally occur twice a month—during new and full moons, when the Earth, Sun, and Moon line up in a row. In this arrangement, the gravities of the Sun and Moon work together and have the strongest pull on Earth. This produces the largest difference between high and low tide.
Spring Tides
During full moon or new moon phases, the gravitational forces of the Sun and Moon are maximized, producing very large ranges of tidal highs and lows called spring tides
