Answer:
when the water is heated with immersion heater, the water becomes less dense due to which the warm water rises up and the cooler water fills it's space.
Answer:
Explanation:
a )
While breaking initial velocity u = 62.5 mph
= 62.5 x 1760 x 3 / (60 x 60 ) ft /s
= 91.66 ft / s
distance trvelled s = 150 ft
v² = u² - 2as
0 = 91.66² - 2 a x 150
a = - 28 ft / s²
b ) While accelerating initial velocity u = 0
distance travelled s = .24 mi
time = 19.3 s
s = ut + 1/2 at²
s is distance travelled in time t with acceleration a ,
.24 = 0 + 1/2 a x 19.3²
a = .001288 mi/s²
= 2.06 m /s²
c )
If distance travelled s = .25 mi
final velocity v = ? a = .001288 mi / s²
v² = u² + 2as
= 0 + 2 x .001288 x .25
= .000644
v = .025 mi / s
= .0025 x 60 x 60 mi / h
= 91.35 mph .
d ) initial velocity u = 59 mph
= 86.53 ft / s
final velocity = 0
acceleration = - 28 ft /s²
v = u - at
0 = 86.53 - 28 t
t = 3 sec approx .
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).
