The answer is A. <span>Some work input is used to overcome friction. </span>
Answer:
a)
, b)
, c)
.
Explanation:
a) Let assume that car travel on a horizontal surface. The equations of equilibrium of the car are:


After some algebraic handling, the following expression for the propulsion force is constructed:



b) The power require to move the car at a speed of 5 meters per second is:



c) The efficiency of the car is:


Answer:
a)-2m/s^2
b)27.2m/s
Explanation:
Hello! The first step to solve this problem is to find the mass of the block remembering that the definition of weight force is mass by gravity (g=9.8m / s ^ 2)
W=455N=weight
W=mg
W=455N=weight

The second step is to draw the free body diagram of the body (see attached image) and use Newton's second law that states that the sum of the forces is equal to mass by acceleration

for point b we use the equations of motion with constant acceleration to find the velocity

Where
Vf = final speed
Vo = Initial speed
=0
A = acceleration
=2m/s
X = displacement
=6.8m
Solving
