Answer:
f = 2 Hz
Explanation:
The frequency of a wave is defined as the no. of waves passing per unit of time. Therefore, the frequency of a wave can be calculated by the following formula:

where,
f = frequency of the wave = ?
t = time passed = 1 s
n = no. of waves passing in time t = 2
Therefore,

<u>f = 2 Hz</u>
Answer:
6 km/h
Explanation:
V avg = ∆x/∆t = 3km / 30 min ×(60min/1h) = 3 km× 2 /h = 6 km/h
█ Question <span>█
</span><span>In an electronic transition, an atom cannot emit what?
</span>█ Answer █
When an electronic transition is occurring, an atom cannot emit ultra-violet light.
<span>Hope that helps! ★ <span>If you have further questions about this question or need more help, feel free to comment below or leave me a PM. -UnicornFudge aka Nadia</span></span>
Answer:
B. normal force
Explanation:
Because there is no frictional or resistance force. However gravitational force is applied downroad from the center of the cup thus the contact force that is perpendicular to the surface that an object contacts which is the normal force exerted upward from the table that prevents an object from falling.
Answer:MOST COMMON METHOD IS USING A LUBRICANT -
A lubricant is a substance, usually organic, introduced to reduce friction between surfaces in ... medical examination. It is mainly used to reduce friction and to contribute to a better and efficient functioning of a mechanism. ... For lubricant base oil use, the vegetable derived materials are preferred
OTHER METHODS-
There are a number of ways to reduce friction:
Make the surfaces smoother. ...
Lubrication is another way to make a surface smoother.
Make the object more streamlined.
Reduce the forces acting on the surfaces.
Reduce the contact between the surfaces.
PLEASE DO MARK ME AS THE BRAINLIEST :)