A worker with a wheelbarrow filled with bricks starts at a point 50 m from the entrance to a construction site. The worker pushes the wheelbarrow away from the
entrance at a speed of 1 m/s for 10 s, stops for 5 s to unload, and then moves back
toward the entrance at a speed of 2 m/s for 20 s. Draw a distance-time graph.

Step-by-step explanation:

initial distance, d = 50 m at t = 0 s

t = 10 s , speed, v = 1 m/s

distance, d' = 1 x 10 = 10 m at t = 10 s

Now t = 10 s to t = 15 s it is at rest

speed, v' = 20 m/s , t' = 20 s

distance, d'' = 2 x 20 = 40 m at t = 15 s to 35 second

The graph is given below:

u = -(6/7)w

step-by-step explanation:

place all values with 'u' on one side of the equation.

4u + 8w = - 3u + 2w

4u + 3u = 2w - 8w

further simplify the equation by solving the addition and subtraction.

7u = - 6w

make 'u' the independent variable by placing its co-efficient on the right-hand side.

u = - (6/7)w