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:
IV, Type of dish detergent. DV, height of foam. CV, type of container, amount of water in container, temperature of water, time the container is agitated.
Explanation:
Independent variable(IV)- what you change during the experiment.
dependent variable(DV)- what you're measuring during an experiment. The dependent variable is DEPENDENT because it's results DEPEND on the independent variable at play.
Constant variables(CV)- things that do not change in order to isolate the tested variables as much as possible.
Answer:
Explanation:
A )
speed of swimming in still water is given by the expression
distance / time
= 50 / 25
= 2 m /s
In lane 1 , 1.2 cm/s current is flowing in the direction that the swimmers are going so swimmers will cover distance at the rate of 2 + 1.2 = 3.2 m /s.
time to cover distance of 50 m in lane 1
= distance / speed
= 50 / 3.2 = 15.625 s
In lane 8 , 1.2 cm/s current is flowing against the direction that the swimmers are going so swimmers will cover distance at the rate of 2 - 1.2 = .8 m /s.
time to cover distance of 50 m in lane 1
= distance / speed
= 50 / .8 = 62.5 s
Answer:
A. Two tennis balls that are near each other
Explanation:
The formula for gravitational force (F) between two objects is

where m₁ and m₂ are the masses of the two objects, d is the distance between their centres, and G is the gravitational constant.
Thus, two objects that are far from each other will have a smaller gravitational force. We can eliminate Options C and D.
If the objects are at the same distance, those with the smaller mass will have a smaller force.
The mass of a tennis ball is 57 g.
The mass of a soccer ball is 430 g.
Two tennis balls that are near each other will have a smaller gravitational attraction.
Answer:
f=force m=mass and a=acceleration