1575 N
Explanation:
Step 1:
Let us consider that 350 J of energy is spent by that person to push a couch to 4.5 m from its initial position.
Let F be the force required and E be the energy spent and D be the distance traveled by the couch from its initial state.
In Physics, Work done = Force / Displaced distance
Step 2:
Let the work done be 350 J and Distance be 4.5 m
Then Force exerted = 
Answer:
4 m/s or 4 meters per second.
Explanation:
In order to calculate the speed of wave, you multiply the wavelength in meters and the frequency of the Wave in Hertz. 2 times 2 equals 4. The wave speed is always in m/s considering that the wavelength is also in meters.
#Case -1
If Pulling force is less than frictional force the object won't move .
#Case-2
If Pulling force is greater than frictional force then object will be .
In order to calculate friction force you need Limiting friction first .

u s is coefficient of static friction and N is normal reaction
Or

Answer:

Explanation:
You need to be careful with units for this problem. The force will be:


