Answer:
Explanation:One method of calculating average speed is to divide the total distance by the total time spent
d1=d2= 12 miles
d1=d2= 19312.1 m
There is slight difference between the average speeds due to the reason that average speed is not just the midpoint of the speed but is the total distance traveled by total time.
Answer:
a) E = 2.00 10³ J
, b) I = 6.66 10⁻⁶ N s
, c) F = 1.66 10⁻⁶ N
Explanation:
a) The intensity is defined as the power per unit area
I = P / A
P = I A
Power is energy for time
P = E / t
We replace
E / t = I A
E = I A t
E = 1.0 10³ 2.0 1.00
E = 2.00 10³ J
b) The moment is
p = U / c
In the case of a reflection the speed is reversed, so the moment
Δp = 2 U / c
I = Δp
I = 2 U / c
I = 2.00 10³/3 10⁸
I = 6.66 10⁻⁶ N s
c) The defined impulse is
I = F t
F = I / t
For a time of 1 s
F = 6.66 10⁻⁶ / 1
F = 1.66 10⁻⁶ N
d) Suppose n small mass mirror m = 10 10⁻³ kg, we write Newton's second law
F = ma
a = F / m
a = 1.66 10⁻⁶ / 10 10⁻³
a = 1.66 10⁻⁴ m / s
We see that the acceleration is very small and attended to increase the mass of the mirror will be less and less, so the assumption of no twisting of the mirror is very reasonable
