Answer:
The angle of incident ray is 40°.
Explanation:
Given that the angle of incident and reflected ray are the same. In this question, we had given that both angles added up will gives you 80° so you have to divide it by 2 :
incident + reflected = 80°
Let incident = reflected = θ
θ + θ = 80°
2θ = 80°
θ = 80° ÷ 2
= 40°
Answer:

Explanation:
Since fluid is pumping in and out at the same rate (5L/min), the total fluid volume in the tank stays constant at 350L. Only the amount of salt and its concentration changed overtime.
Let A(t) be the amount of salt (g) at time t and C(t) (g/L) be the concentration at time t
A(0) = 10 g
Brine with concentration of 1g/L is pouring in at the rate of 5L/min so the salt income rate is 5 g/min
The well-mixed solution is pouring out at the rate of 5L/min at concentration C(t) so the salt outcome rate is 5C g/min
But the concentration is total amount of salt over 350L constant volume
C = A / 350
Therefore our rate of change for salt A' is
A' = 5 - 5A/350 = 5 - A/70
This is a first-order linear ordinary differential equation and it has the form of y' = a + by. The solution of this is

So 
with A(0) = 10
c + 350 = 10
c = 10 - 350 = -340

Answer:
536.56 m/s
Explanation:
We'll begin by calculating the momentum of the Porsche. This can be obtained as follow:
Mass (m) of Porsche = 1361 kg
Velocity (v) of Porsche = 26.82 m/s
Momentum of Porsche =?
Momentum = mass × velocity
Momentum = 1361 × 26.82
Momentum of Porsche = 36502.02 Kgm/s
Finally, we shall determine the velocity you need to be running with in order to have the same momentum as the Porsche. This can be obtained as follow:
Your Mass = 68.03 kg
Your Momentum = Momentum of Porsche = 36502.02 Kgm/s
Your velocity =?
Momentum = mass × velocity
36502.02 = 68.03 × velocity
Divide both side by 68.03
Velocity = 36502.02 / 68.03
Velocity = 536.56 m/s
Thus you must be running with a speed of 536.56 m/s in order to have the same momentum as Porsche.
Answer:
27.1m/s
Explanation:
Given parameters:
Height of the building = 30m
Initial velocity = 12m/s
Unknown:
Final velocity = ?
Solution:
We apply one of the kinematics equation to solve this problem:
v² = u² + 2gh
v is the final velocity
u is the initial velocity
g is the acceleration due to gravity
h is the height
v² = 12² + (2 x 9.8 x 30)
v = 27.1m/s
Explanation:
P =F * v
F = m * a = 65 kg * 9.81 ms^-2 * 12 passengers
v = d/t = 150m / 64 s
I think you can calculate and substitute this units should be watts