Answer:

Explanation:
Given the absence of non-conservative force, the motion of the coin is modelled after the Principle of Energy Conservation solely.



The moment of inertia of the coin is:

After some algebraic handling, an expression for the maximum vertical height is derived:




Answer:
C1 + C2 = 30 parallel connection
C1 * C2 / (C1 + C2) = 7.2 series connection
C1 * C2 = 7.2 * (C1 + C2) = 216
C2 + 216 / C2 = 30 using first equation
C2^2 + 216 = 30 C2
C2^2 - 30 C2 + 216 = 0
C2 = 12 or 18 solving the quadratic
Then C1 = 18 or 12
Answer: It takes 2.85 seconds.
Explanation: according to the question, the kinematics equation for vertical motion is

y₀ is the initial postion and equals 0 because it is fired at ground level;
v₀ is the initial speed and eqauls 14m/s;
g is gravity and it is 9.8m/s²;
y(t) is the final position and equals 0 because it is when the pumpkin hits the ground;
Rewriting the equation, we have:
0 + 14t -
= 0
14t - 4.9t² = 0
t(14 - 4.9t) = 0
For this equation to be zero,
t = 0 or
14 - 4.9t = 0
- 4.9t = - 14
t = 
t = 2.86
It takes 2.86 seconds for the pumpkin to hit the ground.
Answer:
Option A
The apparent change in frequency of waves due to the motion of a source
Explanation:
Doppler effect is the apparent change in frequency of waves due to the motion of a source. Doppler effect occurs when the source of waves moves towards the observer which causes emission of successive wave crests to be closer to the observer compared to the previous wave crest. This phenomenon was named after Austrian Physicist called Christian Doppler
Answer:
Car 1 and Car 2 have the same momentum!
Explanation:
Using the formula of momentum (P=m*v), we get for each car:
Car 1: 5kg*2.2m/s = 11kg*m/s
Car 2: 5.5kg*2m/s = 11kg*m/s
Car 3: 6kg*1.35m/s = 8.1kg*m/s
Car 4: 6.5kg*1.9m/s = 12.35kg*m/s
Car 5: 7kg*1.25m/s = 8.75kg*m/s