Answer:
hence option A is correct
Explanation:
heat required from -9°C to 0°C ice = mass × specific heat of ice ×change in temperature
heat required from -9°C to 0°C ice = 7×2100×9 =132300 J =0.1323 MJ
( HERE SPECIFIC HEAT OF ICE IS A CONSTANT VALUE OF 2100
J/(kg °C )
heat required from 0°C ice to 0°C water = mass× specific heat of fusion of ice
= 7×3.36×10^5
= 2.352 × 10^6 J
= 2.352 MJ
TOTAL HEAT ENERGY REQUIRED = 0.1323 MJ +2.352 MJ
= 2.4843 MJ
hence option A is correct
Answer:
6 atm.
Explanation:
Let the mass of both be m
Then moles of He = m/ 4
Moles of Ne = m/ 20
mole fraction of He = Moles of He/ Total moles = m/4/ (m/4 + m/20) = 0.25 m/0.3m = 0.83
Pressure of He = Mole fraction×total pressure = 0.83 × 6 atm = 5 atm
The horizontal velocity was constant, so:
it traveled 90meters
Answer:
7 meters, 2.8 meters
Explanation:
work done (nm) = force (n) * distance (m)
140= 20 * m
140/20 = m
m=7 meters
140= 50 * m
140/50 = m
m= 2.8 meters
Answer:
(A) 1.43secs
(B) -2.50m/s^2
Explanation:
A commuter backs her car out of her garage with an acceleration of 1.40m/s^2
(A) When the speed is 2.00m/s then, the time can be calculated as follows
t= Vf-Vo/a
The values given are a= 1.40m/s^2 , Vf= 2.00m/s, Vo= 0
= 2.00-0/1.40
= 2.00/1.40
= 1.43secs
(B) The deceleration when the time is 0.800secs can be calculated as follows
a= Vf-Vo/t
= 0-2.00/0.800
= -2.00/0.800
= -2.50m/s^2
