Answer:
option (c)
Explanation:
According to the doppler's effect, the frequency of sound decreases.
If there is a relative motion between the source and the observer, the frequency of sound changes apparently.
the formula of the doppler effect is given by
where, f is the real frequency, v be the speed of sound, vo be the speed of the observer, here, the bus is the observer.
So, the value of f' < f
A.) For letter a, we use the law of universal gravitation using the constant G = 6.674×10−<span>11 m3</span>⋅kg−1⋅s−<span>2
Grav. F = G*m1*m2*(1/d^2)
m1 is mass of electron = </span>9.11 × 10-31<span> kg
m2 is mass of proton = </span>1.67 × 10<span>-27 kg
d = 4.5 nm = 4.5 x 10^-9 m
Grav F = 5.01 x 10^-51 N
b.) </span>For letter b, we use the Coulomb's using the constant k = 9×10^9 N
Electric force = k*Q1*Q2*(1/d^2)
Q1 is charge of electron = -1.6 × 10-19 C
Q2 is charge of proton = +1.6 × 10-19 C
Electric force = 1.14 x 10^-11 N
C) because you could get hurt if certain items fall in it and you are in water
Answer:
3m/s
Explanation:
Given parameters:
Initial speed = 2m/s
Acceleration = 0.5m/s²
Time = 2s
Unknown:
Final speed = ?
Solution:
To solve this problem, we apply the right motion equation;
V = U + at
V is the final speed
U is the initial speed
a is the acceleration
t is the time
V = 2 + (2 x 0.5)
V = 2 + 1
V = 3m/s
