Answer:
a)θ=71.89°
b)NO
Explanation:
Given that
For glass n= 1.38
We know that for air n'=1
The angle for total internal reflection θc given as
sin θc=n'/n
By putting the values
sin θc=n'/n
sin θc=1/1.38
θc=46.43°
n'sinθ = n sinθref
sinθref = cosθc
n'sinθ = n cosθc
1 x sinθ =1.38 x cos 46.43°
θ=71.89°
b)
NO
In order to accelerate the dragster at a speed

, its engine must do a work equal to the increase in kinetic energy of the dragster. Since it starts from rest, the initial kinetic energy is zero, so the work done by the engine to accelerate the dragster to 100 m/s is

however, we must take into account also the fact that there is a frictional force doing work against the dragster, and the work done by the frictional force is:

and the sign is negative because the frictional force acts against the direction of motion of the dragster.
This means that the total work done by the dragster engine is equal to the work done to accelerate the dragster plus the energy lost because of the frictional force, which is

:

So, the power delivered by the engine is the total work divided by the time, t=7.30 s:

And since 1 horsepower is equal to 746 W, we can rewrite the power as
<span>Electric field is proportional to q/d^2, where q is the magnitude of the charge and d is the distance. Since all the given units are identical, we can just compare their relative magnitudes without calculating for the exact values.
A) 3/(0.4)^2 = 18.75
B) 1.5/(0.2)^2 = 37.5
C) 6/(0.4)^2 = 37.5
D) 3/(0.2)^2 = 75
Therefore, choice D has the largest electric field of all.
</span>
Acceleration of the car is 3.375 m/s² and the force of the car moving forward is 5062.5 N
Explanation:
- Acceleration is the rate of change of velocity.
- It is given by the equation, a = change in velocity/time
Here, velocity changes from 0 to 27 m/s and time = 8
⇒ Acceleration = 27 - 0/8 = 27/8 = 3.375 m/s²
- Force is calculated by the equation, F = Mass × Acceleration
- This is based on Newton's second law of motion.
Here, mass of the car = 1500 kg and a = 3.375 m/s²
⇒ Force = 1500 × 3.375 = 5062.5 N
From the given information, we don't know. All we can tell is the net effect of all the changes during those 4 seconds ... the "averages".
The average change in speed is an increase of 72 km/hr (20 m/s) during that time.
The average acceleration is a constant 18 km/hr/sec (5 m/s^2) during the same time.
But both the speed and the acceleration may have gone up or down many times during the 4 seconds.