# physics

posted by .

which of the following is there no net work?

A car accelerates down a hill.
A car travels at constant speed on a flat road.
A car decelerates on a flat road.
A car decelerates as it travels up a hill.

I say its the first one

• physics -

and, you are wrong. Gravity is doing work on the car.

• physics -

the second one

## Similar Questions

1. ### Physics

A car travels at a speed of 25 m/s on a flat stretch of road. The driver must maitain pressure on the accelerator to keep the car moving at a constant speed. Are there any forces doing work on the car?
2. ### Physics

A car travels at a speed of 25 m/s on a flat stretch of road. The driver must maitain pressure on the accelerator to keep the car moving at a constant speed. Are there any forces doing work on the car?
3. ### physics

Cars A and B are racing each other along the same straight road in the following manner: Car A has a head start and is a distance Da beyond the starting line at t=0. The starting line is at x=0. Car A travels at a constant speed Va. …
4. ### Physics

A car travels at a speed of 25 m/s on a flat stretch road. The driver must maintain pressure on the accelerator to keep the car moving at this speed. The car's engine is doing work on the car, yet the kinetic energy of the car is not …
5. ### Physics

A car travels at a speed of 25 m/s on a flat stretch road. The driver must maintain pressure on the accelerator to keep the car moving at this speed. The car's engine is doing work on the car, yet the kinetic energy of the car is not …
6. ### Physics

a car travels at 25m/s on a flat stretch of road. The driver must maintaint he pressure on the accelerator to keep the care moving at this speed. What is the net work done on the car over a distance of 250m?
7. ### Physics

a car travels at 25m/s on a flat stretch of road. The driver must maintaint he pressure on the accelerator to keep the care moving at this speed. What is the net work done on the car over a distance of 250m?
8. ### physics

1. A car travels down a straight, flat, level road. Initially, the car is traveling at 80.0 km/hr Northward . After traveling 0.50 0 km , the car is traveling at 95 .0 km/hr. What is the magn i tude of the car ’ s acceleration during …
9. ### Physics

A car of mass 1000kg is travelling along a straight flat road at a constant speed of 30.0ms^-1. It then accelerates with constant acceleration of 3.00ms^-2 for 10.0s, after which it continues to travels at a constant speed. Determine: …
10. ### physics (urgent)

A car of mass 1000kg is travelling along a straight flat road at a constant speed of 30.0ms^-1. It then accelerates with constant acceleration of 3.00ms^-2 for 10.0s, after which it continues to travels at a constant speed. Determine: …

More Similar Questions