Answer:
Ball hit the tall building 50 m away below 10.20 m its original level
Explanation:
Horizontal speed = 20 cos40 = 15.32 m/s
Horizontal displacement = 50 m
Horizontal acceleration = 0 m/s²
Substituting in s = ut + 0.5at²
50 = 15.32 t + 0.5 x 0 x t²
t = 3.26 s
Now we need to find how much vertical distance ball travels in 3.26 s.
Initial vertical speed = 20 sin40 = 12.86 m/s
Time = 3.26 s
Vertical acceleration = -9.81 m/s²
Substituting in s = ut + 0.5at²
s = 12.86 x 3.26 + 0.5 x -9.81 x 3.26²
s = -10.20 m
So ball hit the tall building 50 m away below 10.20 m its original level
Answer:
The correct answer is b, x = 9 cos (pi / 2 t)
Explanation:
The equation that describes a simple pendulum is
θ = θ₀ cos (wt + φ)
The angle is measured is radians
θ = x / L
We replace
d / L = x₀ / L cos (wt + φ)
x₀ = 9 in
We replace
d = 9 cos (wt + φ)
Angular velocity is related to frequency and period.
w = 2π f = 2π / T
The period is the time of a complete oscillation T = 4 s
w =2π / 4
w = π / 2
Let's replace
x = 9 cos (π/2 t + φ)
As the system is released from the root x = x₀ for t = 0 s
x₀ = x₀ cos φ
Cos φ = 1
φ = 0°
The final equation is
x = 9 cos (pi / 2 t)
The correct answer is b
Answer: Distance= 100,000 km
Mass= 15 million kg Mass= 5 million kg
To calculate force, use the formula force equals mass times acceleration, or F = m × a. Make sure that the mass measurement you're using is in kilograms and the acceleration is in meters over seconds squared. When you've solved the equation, the force will be measured in Newtons.
Answer:
The photoelectric effect occurs only for frequencies above the cutoff frequency, regardless of the intensity.
Explanation:
The photoelectric effect occurs when light is shined on metals such as zinc beyond a certain frequency (the threshold frequency), which causes electrons to escape from the zinc. The electrons which are fleeing are called photo electrons.
Therefore photo electric effect is
The photoelectric effect occurs only for frequencies above the cutoff frequency, regardless of the intensity.
