Answer:
Explanation:
Acceleration is the time rate of change of velocity.
Acceleration and velocity are vectors
If east and north are the positive directions, the east moving vector is reduced to zero and the north moving vector increases from zero to 4 m/s.
There are 3 hours or 10800 seconds between 10 AM and 1 PM
a1 = √((-4)² + 4²) / 10800 = (√32) / 10800 m/s² ≈ 4.2 x 10⁻⁴ m/s²
There are 14400 seconds between 10 AM and 2 PM
The velocity changes are still the same
a2 = √((-4)² + 4²) / 10800 = (√32) / 14400 m/s² ≈ 3.9 x 10⁻⁴ m/s²
Answer:
3.6 m
Explanation:
let x = horizontal distance between emily and allison should be for allison to catch the ball
Find horizontal speed of the ball
vx = 12 sin 30 = 12 x 0.5 = 6 m/s
To find time taken, we will use vertical values of the ball motion
Initial velocity in vertical direction
u = 12 cos 30 = 10.392 m/s
let a = g = 9.8m/s2
Use equation of motion
s = ut +1/2at^2
s = vertical distance = 8
8 = (10.392)t + (1/2)(9.8)t^2
8 = (10.392)t + (4.9)t^2
4.9t^2 + 10.392t - 8 = 0
Using formula of quadratic or calculator, we'll find
t = 0.6 and t = -2.72
We pick t=0.6s since it's not logical time in negative
Assuming no air resistance or external forces, the ball will move 6m/s horizontally. Hence using the formula of speed
speed vx = distance x / time
x = (vx)(t)
= 6 x 0.6
= 3.6 m
Answer: 8.1 x 10^24
Explanation:
I(t) = (0.6 A) e^(-t/6 hr)
I'll leave out units for neatness: I(t) = 0.6e^(-t/6)
If t is in seconds then since 1hr = 3600s: I(t) = 0.6e^(-t/(6 x 3600) ).
For neatness let k = 1/(6x3600) = 4.63x10^-5, then:
I(t) = 0.6e^(-kt)
Providing t is in seconds, total charge Q in coulombs is
Q= ∫ I(t).dt evaluated from t=0 to t=∞.
Q = ∫(0.6e^(-kt)
= (0.6/-k)e^(-kt) evaluated from t=0 to t=∞.
= -(0.6/k)[e^-∞ - e^-0]
= -0.6/k[0 - 1]
= 0.6/k
= 0.6/(4.63x10^-5)
= 12958 C
Since the magnitude of the charge on an electron = 1.6x10⁻¹⁹ C, the number of electrons is 12958/(1.6x10^-19) = 8.1x10^24 to two significant figures.
Answer:
The simplified expression is 
Explanation:
From the question we are told that
So simplifying we have
Thus the simplified formula is
