Answer:
C. At a particular instant
Explanation:
Speed is the defined as the ratio between the distance covered by an object and the time taken:
where d is the distance and t the time.
However, there are two possible measurements of speed:
- Average speed: this is the speed measured over a non-zero time interval (for example: a car moving 100 metres in 5 seconds; its average speed is
- Instantaneous speed: this is the speed of an object measured at a particular instant in time, so for a time interval that tends to zero. So, in the previous example, the average speed is 20 m/s but the instantaneous speed of the car at various instants of time can be different from that value.
Explanation:
Mass of bumper cars, 
Initial speed of car A, 
Initial speed of car Z, 
Final speed of car A after the collision, 
We need to find the velocity of car Z after the collision. Let it is equal to 
. Using the conservation of momentum as :
So, the velocity of car Z after the collision is (-12 m/s). Hence, this is the required solution.
Answer:
B. Radiowaves
Explanation:
Radiowaves are on the higher end of the spectrum, then infrared, visible light, and UV light (which is the lowest energy)
Given,
A player kicks a soccer hits at an angle of 30° at a speed of 26 m/s
We can resolute the trajectory of soccer into horizontal and vertical components.(Please see the attached file)
We can have,
Horizontal velocity component of ball= 26cos(30°) = 26×(√3÷2) = 22.51 m/s
And vertical velocity component of ball = 26sin(26°) = 26×(1÷2) = 13 m/s
