Answer:
a) 
b) 
Explanation:
Given:
- efficiency of the motor,

- voltage of the battery,

- mass of the car,

a)
initial velocity, 
final velocity, 
time taken for the acceleration, 
Now we know by the Newton's second law of motion:



Now the power will be :



<u>According to the question:</u>
0.95 times of the electrical power should yield this mechanical power.




b)
height climbed by the car, 
velocity of climb, 
time taken to climb the height, 
force exerted to overcome air and frictional resistances, 
Now the Power required to climb the hill:



<u>Now according to the electrical efficiency:</u>



Finally, the amount of increased volume<span> that is achieved by an increase in </span>amplitude<span>is also affected by the frequency. So, turning the </span>amplitude<span> level in the mid-range sound from the previous example will not have the same proportional effect on loudness as the bass sound.</span>
Answer and explanation:
When you are changing a car tire, the most important thing is to keep the total diameter as equal as possible.
The total car tire diameter can be calculated as:

The profile of this tire is 75 (the higher/taller relation), therefore a 5 percent lower profile would be:
pr=0.95·75=71.25
The problem is that the profiles are normalized and the nearest profile available is 70.
If we take a theorical tire with a profile of 71.25:

The theorical tire size should be 205/71 R15.
If we look for a real tire size, we should look for a tire with a diameter nearest to 26.5'' and a profile of 70.
The best option for real tire size is: Tire 225/70 R14 (wheel diameter of 26.4'') or 205/70 R15 (wheel diameter of 26.3'').
Answer:
2361 Newtons
Explanation:
From the second Newton's law of motion;
F = ma
In this case;
we are given;
Mass as 9.5 g
Initial speed as 0 m/s
Final velocity as 650 m/s
Distance is 0.85 m
Using the equation;
V² = U² + 2as
But u = 0
v² = 2as
Therefore;
a = v² ÷ 2s
= 650² ÷ 2(0.85)
= 248,529.40 m/s²
But;
F = ma
= 0.0095 kg × 248,529.40 m/s²
= 2361 Newtons
Therefore;
The average net force required to accelerate the bullet is 2361 Newtons.