The speed of electromagnetic waves in a vacuum is the same as the speed of light. It can be measured by finding the frequency and wavelength of two different waves, and then by that correlation, the speed of the waveform.
Hope this helps you (:
Answer:
0.2s
force = change in momentum/ time
time = change in momentum/time
Explanation:
first, let's find the change in momentum
pf-pi
5×(-2) - 5× 2
-20kgm/s = 20kgm/s(by changing the direction of whole system)
time = change in momentum/time
20/100
<u> 0.2s</u>
Answer:
Option A. 40 mi/h
Explanation:
To obtain the average speed of the vehicle, we'll begin by calculating the distance travelled by the vehicle in each case. This is illustrated below:
Case 1:
Speed = 30 mi/h
Time = 2 h
Distance =...?
Speed = Distance /Time
30 = Distance /2
Cross multiply
Distance = 30 × 2
Distance = 60 mi
Case 2:
Speed = 60 mi/h
Time = 1 h
Distance =...?
Speed = Distance /Time
60 = Distance /1
Cross multiply
Distance = 60 × 1
Distance = 60 mi
Finally, we shall determine the average speed of the vehicle as follow:
Total distance travelled = 60 + 60
Total distance travelled = 120 mi
Total time = 2 + 1
Total time = 3 h
Average speed =..?
Average speed = Total Distance travelled /Total time
Average speed = 120/3
Average speed = 40 mi/h
Therefore, the average speed of the vehicle is 40 mi/h
Answer:
(a) 
(b) 
Explanation:
We will take ground level as origin and upward is positive direction
the givens are
Part (a)
To find the final velocity we use the kinematic equation
So
Part (b)
To find time of rock trip until it touches the ground we will use simple kinematic equation or simple motion equation
Notice that we substituted vf with negative sign because its direction is downwards
