First half:
50 km at 50 km/hr ... 1 hour
Second half:
50 km at 100 km/hr ... 1/2 hour
Total distance = 100 km
Total time = 1.5 hours
Average speed = (100 km) / (1.5 hrs)
Average speed = 66 and 2/3 km/hr
Average velocity = 66 and 2/3 km/hr East
First you find the frequency which is. 1/T(period) so u get 1*10^10
Now that you know frequency u can solve for speed: s= wavelength* frequency, but don't forget to convert 3cm into meters: 3/100= .03m so now you do (1*10^10)(.3)= 300,000,000 m/s or 3*10^8 m/s
Hope this helped :))
Answer:
Transverse
Explanation:
Electromagnetic waves don't depend on the medium they travel through like a mechanical wave does, so they aren't mechanical. They don't oscillate (move back in forth) in the direction they travel either, ruling out compressional and longitudinal waves.
That leaves tranverse waves, the ones we're most used to, since they look very "wavelike," with smooth peaks and valleys. Electromagnic waves behave like these, oscillating in a plane perpendicular to the direction they're traveling in.
Answer:
<em>The coefficient of static friction between the crate and the floor is 0.41</em>
Explanation:
<u>Friction Force</u>
When an object is moving and encounters friction in the air or rough surfaces, it loses acceleration and velocity because the friction force opposes motion.
The friction force when an object is moving on a horizontal surface is calculated by:
[1]
Where
is the coefficient of static or kinetics friction and N is the normal force.
If no forces other then the weight and the normal are acting upon the y-direction, then the weight and the normal are equal in magnitude:
N = W = m.g
The crate of m=20 Kg has a weight of:
W = 20*9.8
W = 196 N
The normal force is also N=196 N
We can find the coefficient of static friction by solving [1] for
:

The friction force is equal to the minimum force required to start moving the object on the floor, thus Fr=80 N and:


The coefficient of static friction between the crate and the floor is 0.41