Answer:
8451.62109367671 Newtons
Explanation:


It is known that

So,

The force in Newtons is 8451.6210936765 Newtons
Answer:
2.5km
Explanation:
Assuming you also walk with the average human walking speed of 5 km/h. We know that speed=distance/time and now making distance the subject, distance is a product of speed and time. The time is 30 minutes, expressed in hours will be 30/60=0.5 hours. Substituting 5km/h for speed and 0.5 hours for time then the diatance covered will be
Distance=5*0.5=2.5 km
Answer:
The acceleration towards the center will be 
Explanation:
Given the running track is an oval shape, and the diameter of each half-circle is 74 meters.
Also, the runner took 1 minute and 40 seconds to complete 400 m one round of the track.
We need to find the acceleration towards the center.
First, we will find the speed.

Where
is the speed.
is the distance covered by the rider that is 400 meters.
is the time taken by the rider to complete the lap which is 1 minute and 40 seconds.
seconds.
So,

And

Where
is the acceleration towards the center.
is the radius which will be the half of the diameter 74 meters.
Hence, the radius will be 37 meters.

So, the centripetal acceleration of the rider will be 
Yes, you can. Remember that in electrophysics, opposite charges attract. Since there is a stand of rotation, it allows the rod with both ends having opposite charges to rotate. Now, if you place the unknown charge near the set-up, it could turn clockwise or counterclockwise. When the set-up turns such that the negative end is approaching the unknown charge, that charge must be positive. Otherwise, the unknown charge is negative.
The answer should be B - lasts longer.