Answer:

I guess you can round it to 11 seconds.
Explanation:
Going with a speed 9m/s means you are going 9 meters in each second.
If you are going 9 meters in second how many seconds will it take to 100 meters?
Visually;
9 meters - - - 1 second
100 meters - - - ?seconds.
When you write like this 9 times ?seconds equal to 100 meters time 1 second. (you probably know this but just in case)
So to find ?second you multiply 100meters by 1 and divide it by 9 whixh will give you 11.1111 seconds whixh again I believe you can round it to 11.
(Kind of a) Proof;
If 9m * ?sec = 100 m * 1 sec
you send 9 meters to other side.
?sec = (100 m * 1 sec) ÷ 9m
Hope it was clear and it helps! Please let me know if you have any questions.
Explanation:
In vector geometry, the resultant vector is defined as: “A resultant vector is a combination or, in simpler words, can be defined as the sum of two or more vectors which has its own magnitude and direction.”
I hope it's helpful!
Find the force that would be required in the absence of friction first, then calculate the force of friction and add them together. This is done because the friction force is going to have to be compensated for. We will need that much more force than we otherwise would to achieve the desired acceleration:

The friction force will be given by the normal force times the coefficient of friction. Here the normal force is just its weight, mg

Now the total force required is:
0.0702N+0.803N=0.873N
Answer:
If the system consists of the block only, the work done by the gravity is negative.
If the system consists of the block and the earth the work done by the gravity is zero.
Explanation:
If the system consists of the block only, then the system experiences two external forces: one exerted by the hand that lifts the block vertically upward and other exerted by the earth (gravity), which is opposed to the movement of the system, so the work done by gravity is negative.
On the other hand, if the system consists of the block and the earth, then only exists a external force which is the exerted by the hand. So, the force exerted by gravity is zero.