Answer:
Air resistance have some significant role in projectile motion if the motion lasts for some time.
Explanation:
- Air resistance or air drag seems to be important in daily actvities and games like baseball.
- The trajectory of the projectile with or without air resistance or air drag is totally different.
- When we neglect air drag, the only acting force is gravity against the motion so the maximum height and range are suppose Hmax and R.
- Now, when we consider air drag, it is important to notice that there are two forces against the motion of the ball and along the direction of gravity. It seems that both maximum height and range are lesser Hmax'< Hmax and R'<R.
Velocity =displacement
Change in time
D=72km/hr
Time=20s
But the S.I unit of velocity is m/s so you woul have to change 72km/hr to m/s
Changing 72km to m
1 kilometer=1000meters
Then, 72 kilometers =?
72•1000/1
=72000m
Changing 72hours to seconds
If 1 hour = 3600 seconds
Then 72 hours=?
72•3600/1
=259200 seconds
Velocity =displacement
Change in time
V= 72,000
259,2005
=0.028m/s
Answer:
The Answer is false
Explanation:
Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.
Guessing you want the average speed. We can multiple each speed by the time we spent going that speed, and them all together and then divide by the total time we spent in traffic to get the average speed. We spent a total of 7.5 minutes in traffic, so average speed = (12*1.5+0*3.5+15*2.5)/7.5 = 7.4 m/s
