Answer:
Graph B represents correct graph for velocity time
Explanation:
Initially the object is dropped under the influence of constant force due to gravity
So here we can say its acceleration is constant due to gravity
hence here the velocity will increase downwards due to gravity and it is given as

now when it enters into the pool an upward force of same magnitude will act on it
so net force on it is

so here we will have no acceleration and it will move with constant speed after that
so here correct graph is
Graph B
Answer: 146.1 kg/m/s
Explanation: Momentum is equal to mass times velocity, so you do 9.74 kg times 15 m/s and get 146.1 kg/m/s.
Answer:
The total amount of CO₂ produced will be = 20680 kg/year
The reduction in the amount of CO₂ emissions by that household per year = 3102 kg/year
Explanation:
Given:
Power used by household = 14000 kWh
Fuel oil used = 3400 L
CO₂ produced of fuel oil = 3.2 kg/L
CO₂ produced of electricity = 0.70 kg/kWh
Now, the total amount of CO₂ produced will be = (14000 kWh × 0.70 kg/kWh) + (3400 L × 3.2 kg/L)
⇒ The total amount of CO₂ produced will be = 9800 + 10880 = 20680 kg/year
Now,
if the usage of electricity and fuel oil is reduced by 15%, the reduction in the amount of the CO₂ emission will be = 0.15 × 20680 kg/year = 3102 kg/year
Answer:
7200 N/m
Explanation:
Metric unit conversion
100g = 0.1 kg
5 cm = 0.05 m
50 cm = 0.5 m
As the block is released from the spring and travelling to height h = 1.5m off the ground, the elastics energy is converted to work of friction force and the potential energy at 1.5 m off the ground
The work by friction force is the product of the force F = 15N itself and the distance s = 0.5 m

Let g = 10 m/s2. The change in potential energy can be calculated as the following:

Therefore, as elastic energy is converted to potential energy and work of friction:



The balance chemical reaction is:
<span>6 Li(s) + N2(g) → 2 Li3N(s)
We use the amount of the Lithium reactant and the relations of the substances from the reaction to calculate the amount of product produced. We do as follows:
1.75 mol Li ( 2 mol Li3N / 6 mol Li ) (34.83 g / mol) = 20.32 g Li</span>