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:
2.5 kg.m/s
Explanation:
Taking left side as positive while right side direction as negative then
Momentum, p= mv where m is the mass of the object and v is the velocity of travel
Momentum for ball moving towards right side=mv=2.5*-3=-7.5 kg.m/s
Momentum for the ball moving towards the left side=mv=2.5*4=10 kg.m/s
Total momentum=-7.5 kg.m/s+10 kg.m/s=2.5 kg.m/s
To calculate the gravitational force acting on an object given the mass and the acceleration due to gravity, use the following formula.
Fg = m • g
Fg = 1.3 kg • 9.8 m/s^2
Fg = 12.74 N or about 12.7 N.
The solution is C. 12.7 N.
