Answer:
The net power needed to change the speed of the vehicle is 275,000 W
Explanation:
Given;
mass of the sport vehicle, m = 1600 kg
initial velocity of the vehicle, u = 15 m/s
final velocity of the vehicle, v = 40 m/s
time of motion, t = 4 s
The force needed to change the speed of the sport vehicle;

The net power needed to change the speed of the vehicle is calculated as;
![P_{net} = \frac{1}{2} F[u + v]\\\\P_{net} = \frac{1}{2} \times 10,000[15 + 40]\\\\P_{net} = 275,000 \ W](https://tex.z-dn.net/?f=P_%7Bnet%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20F%5Bu%20%2B%20v%5D%5C%5C%5C%5CP_%7Bnet%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20%5Ctimes%2010%2C000%5B15%20%2B%2040%5D%5C%5C%5C%5CP_%7Bnet%7D%20%3D%20275%2C000%20%5C%20W)
Answer:
The ratio of electric force to the gravitational force is 
Explanation:
It is given that,
Distance between electron and proton, 
Electric force is given by :

Gravitational force is given by :

Where
is mass of electron, 
is mass of proton, 
is charge on electron, 
is charge on proton, 



So, the ratio of electric force to the gravitational force is
. Hence, this is the required solution.
Explanation:
It is given that,
Speed, v₁ = 7.7 m/s
We need to find the velocity after it has risen 1 meter above the lowest point. Let it is given by v₂. Using the conservation of energy as :




So, the velocity after it has risen 1 meter above the lowest point is 6.26 m/s. Hence, this is the required solution.
Answer:
Groceries stay in the bag.
Explanation:
Given:
Maximum force = 250 N
Bag filled with = 20 kg
Lifted acceleration = 
Solution:
We need to calculate the exerted force on the grocery bag by using Newton's second law.

Where:
F = Exerted force on the object.
m = Mass of the object in kg
a = Acceleration of the object in 
Now, we substitute m = 20 kg and a =
in Newton's second law,


Since, the exerted force on the bag is less than 250 N, the groceries will stay in the bag.
Answer:
Both substance will melt and become a solution.
Explanation:
When a mixture of iron filings (black substance) and sulphur powder (yellow substance) are heated in a test tube under a bunsen burner, usually they will undergo a chemical reaction where they will melt to form a new solution of ferrous sulphide.
Thus, we can say what happens is that both substances melt to form a solution.