Some examples of constant velocity (or at least almost- constant velocity) motion include (among many others): • A car traveling at constant speed without changing direction. A hockey puck sliding across ice. A space probe that is drifting through interstellar space.
Answer:
Are you trying to calculate the net force?
If so, it would be 3 N Up.
This is because the 15 N forces from the left and right cancel out, leaving only the upwards 15 N force, and the 12 N force. However, we have to subtract 12 from 15, leaving the final net force to be 3 N Up.
Let me know if this helps!
Factors affecting friction
The intensity of friction depends on following factors: i) The area involved in friction. ii) The pressure applied on the surfaces. Force = Pressure ´ Area Frictional force will increase, if the area of contact will increase or if pressure applied on the surface increased.
Methods to reduce friction
i) Polish the contact surface. ii) Put oil or grease so that it fills in the small gaps of the flat parts. iii) Use ball bearings to reduce area of contact between rotating parts.
Lubrication
Following methods can be used to reduce friction: Oil is either thin or viscous. It depends upon SAE No. of oil. (SAE means Society of Automotive Engineers). If we use very viscous oil, it does not reach all the parts. Very thin oil will flows away easily and gets wasted. Grease is used in such cases. It is generally used around ball-bearing. Normal grease or oil is never used where there is high pressure, high temperature and high speed. Special lubricants are used in such cases. In cold season the oil becomes thick and in hot season it becomes thin. Therefore selection of lubrication also depends on the season. It is always advisable to refer operating manual of the equipment before selecting the lubricant.
Answer:
~The slope of the line on a velocity vs. time graph represents acceleration.
Explanation:
~~Acceleration is equal to the ratio between the change in velocity of an object and the time taken:
a=\frac{\Delta v}{\Delta t}a=
Δt
Δv
On a velocity-time graph, this ratio corresponds to the slope of the line. In fact, \Delta vΔv corresponds to the increment in the y-value (the velocity), while \Delta tΔt corresponds to the increment in the x-value (the time), therefore their ratio corresponds to the definition of slope of the line.
