The direction of friction force is always the opposite of the direction of the movement.
In this problem, we have an applied force of 20N and this creates a movement. Then, the friction comes in and applies a force of 2.4N.
Because they are in different directions, we need to subtract them:
We don't know the direction because there is no picture (at least I can't see ☺️). But the movement will be to the direction of the 20N.
Answer:
5 watts
power = work done ÷ time taken
10 j ÷ 2 = 5w
A. Insulator paper is a good insulator of heat
Answer:
21.53 x 10^{6} N
Explanation:
force (F) = 4.71 x 10^{3} N
distance (s) = 4.57 km = 4570 m
how much work is done.
work = force x distance
work = 4.71 x 10^{3} x 4570 = 21.53 x 10^{6} N
For uniform acceleration (or deceleration in this case), you use the formula:
Vf = Vi + at
Vi = 22 m/s
Vf = 0 (coming to a stop)
t = 5 sec
Plugging everything into the formula gives you:
0 = 22 + 5a
-22 = 5a
a = -22/5 or -4.4 m/s^2
Hope this helps!