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:
Q = 7272 Kilojoules.
Explanation:
<u>Given the following data;</u>
Mass = 2.0*101kg = 202kg
Initial temperature, T1 = 10°C
Final temperature, T2 = 90°C
We know that the specific heat capacity of iron = 450J/kg°C
*To find the quantity of heat*
Heat capacity is given by the formula;
Where;
- Q represents the heat capacity or quantity of heat.
- m represents the mass of an object.
- c represents the specific heat capacity of water.
- dt represents the change in temperature.
dt = T2 - T1
dt = 90 - 10
dt = 80°C
Substituting the values into the equation, we have;
Q = 7272KJ or 7272000 Joules.
Answer:
4.22 m
Explanation:
Una rampa es una máquina que se utiliza para levantar un objeto con una fuerza menor a la que realmente necesitarías. Cuanto mayor sea la longitud de la rampa, menor será la magnitud de la fuerza necesaria para levantar el objeto.
Dado que:
altura de la rampa = 1.5 m, carga = 4900 N, fuerza aplicada = 1633.33 N.
La fórmula de la rampa se da como:
fuerza aplicada * longitud de la rampa = peso de la carga * altura de la rampa
1633.33 * longitud de la rampa = 4900 * 1.5
longitud de la rampa = 4900 * 1.5 / 1633.33
longitud de la rampa = 4.22 m
Answer:
Δy = v₀t + (1/2)gt²
where g = 9.81 m/s if the body is moving downwards and g = -9.81 m/s if the body is moving upwards
Explanation:
The general kinematic equation for horizontal displacement is gives as:
Δx = v₀t + (1/2)at²
Where
Δx = change in the x direction
v₀ = initial velocity
t = time
a = acceleration
If the body is vertically instead of horizontally, Δx is changed to Δy
Δy = v₀t + (1/2)at²
For a vertical moving body, the acceleration it experiences is the gravitational accerelation of the earth 'g'
So the equation becomes:
Δy = v₀t + (1/2)gt²
where g = 9.81 m/s if the body is moving downwards and g = -9.81 m/s if the body is moving upwards
Answer:
c
Explanation:
efficiency is measured in % hence 0.02% is smaller than 20%
