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:
Height h= 1.7 m
Explanation:
Supposing we have to find height in meter.
1 feet = 0.3048 m
1 inch = 0.0254 m
Given that:
5 feet
= 5×0.3048
= 1.524 m
and 7 inch = 7×0.0254= 0.1778 m
Therefore total height of a man in meter
5 feet 7 inch = 1.5424+0.1778 =1.7 m
Height h= 1.7 m
Answer:
Lauch velocity (u) = 26.15 m/s
Lauch Angle (θ) = 35°
Explanation:
From the question given above, the following data were obtained:
Range (R) = 65 m
Time of flight (T) = 3 s
Acceleration due to gravity (g) = 10 m/s²
Lauch velocity (u) =?
Lauch Angle (θ) =?
R = u²Sin2θ /g
65 = u² × Sin2θ /10
Recall:
Sin2θ = 2SinθCosθ
65 = u² × 2SinθCosθ / 10
65 = u² × SinθCosθ / 5
Cross multiply
65 × 5 = u² × SinθCosθ
325 = u² × SinθCosθ .....(1)
T = 2uSinθ / g
3 = 2uSinθ / 10
3 = uSinθ / 5
Cross multiply
3 × 5 = uSinθ
15 = u × Sinθ
Divide both side by Sinθ
u = 15 / Sinθ....... (2)
Substitute the value of u in equation (2) into equation (1)
325 = u² × SinθCosθ
u = 15 / Sinθ
325 = (15 / Sinθ)² × SinθCosθ
325 = 225 / Sin²θ × SinθCosθ
325 = 225 × SinθCosθ / Sin²θ
325 = 225 × Cosθ / Sinθ
Cross multiply
325 × Sineθ = 225 × Cosθ
Divide both side by Cosθ
325 × Sineθ / Cosθ = 225
Divide both side by 325
Sineθ / Cosθ = 225 / 325
Sineθ / Cosθ = 0.6923
Recall:
Sineθ / Cosθ = Tanθ
Tanθ = 0.6923
Take the inverse of Tan
θ = Tan¯¹ 0.6923
θ = 35°
Substitute the value of θ into equation (2) to obtain the value of u.
u = 15 / Sinθ
θ = 35°
u = 15 / Sin 35
u = 15 / 0.5736
u = 26.15 m/s
Summary:
Lauch velocity (u) = 26.15 m/s
Lauch Angle (θ) = 35°
Answer:
Spills out 10cm³ of wather.
Explanation:
The ball being submerged halfway in the full glass of water will spill a volume of water equal to the volume of the ball that is being submerged, because the entire volume of the submerged ball was previously occupied by water and is not compressed should move out of the glass.This volume will be 10cm³ since the total of the ball is 20cm³ and it is submerged halfway.
Explanation:
Given that,
Mass of the particle, m = 4 kg
Speed of the particle, v = 2.5 m/s
The radius of the circle, r = 2 m
We need to find the angular momentum about the center of the circle. The formula for the angular momentum is given by :
Substitute all the values,
So, the angular momentum of the particle is 20 kg-m² s.
