Answer:
12m
Explanation:
To obtain the answer to the question given, we must observe the characteristics of image formed by a plane mirror.
The image formed by a plane mirror have the following characteristics:
1. Laterally inverted.
2. Same distance as the object from the mirror.
3. Same height as the object.
4. Virtual.
With the above information, we can calculate the distance between the boy and his image as follow:
Initially:
Object distance (u) = 4m
Image distance (v) = 4m
The boy moved 2m away, therefore:
Object distance (u) = 2 + 4 = 6m
Image distanc(v) = 2 + 4 = 6m
The distance between the boy and his image will be the sum of his distance (u) and image distance (v) i.e (u + v)
The distance between the boy and his image = 6 + 6 = 12m
Therefore, the distance between the boy and his image is 12m.
Explanation:
Given parameters:
Distance hopped = 84m
Displacement = 84m due east
Time = 7s
Unknown:
Speed of kangaroo = ?
Velocity of kangaroo = ?
Solution:
To solve this problem,
Speed =
=
= 12m/s
Velocity =
=
= 12m/s due east
Answer:
The electron's speed is 34007.35 m/s
Explanation:
It is given that,
Magnetic field, B = 0.34 T
Magnetic force on the electron, 
The electron follows a helical path. We have to find the speed of an electron. The formula for magnetic force is given by :

q = charge on an electron, 
v = velocity of an electron


v = 34007.35 m/s
Hence, this is the required solution.
Answer:
C
Explanation:
C would make the most sense because the problem with fossil fuels is the fact that it emits greenhouse gases that warm up the earth over a long period of time as the climate has changed because of it.