posted by .

way safety engineers build soft barriers
so that cars hitting them will slow down at a
safe rate. A person wearing a safety belt can
withstand an acceleration of 300 m/s
2
.
How thick should barriers be to safely stop
a car that hits the barriers at 81.7 km/h?

v=81.7 km/h =81700/3600=22.7 m/s
d= v²/2a=22.7²/300=1.72 m

## Similar Questions

1. ### physics

Highway safety engineers build soft barriers such as the one shown in Figure 3-21, so that cars hitting them will slow down at a safe rate. A person wearing a safety belt can withstand an acceleration of -3.0 102 m/s2. How thick should …
2. ### Physics

highway saftey engineers build soft barriers so that cars hittingthem will slow down at a safe rate. a person wearing a saftey belt can withstand an acceleration of 300 m/s how thick should barriers be to safely stop a car that hits …
3. ### physics

Highway safety engineers build soft barriers so that cars hitting them will slow down at a safe rate. A person wearing a seat belt can withstand an acceleration of -300 m/s². How think should barriers be to safely stop a car that …
4. ### Physics

Highway safety engineers build soft barriers so that cars hitting them will slow down at a safe rate. A person wearing a seat belt can withstand and acceleration of -3.0 102 m/s2. How thick should barriers be to safely stop a car that …
5. ### science!

1. A plane accelerated from a speed of 2.0 m/s at the rate of 3.0 m/s2 over a distance of 530 m. What is its speed after traveling this distance?
6. ### physics

A person wearing a safety belt can withstand an acceleration of -3.0E2 m/s2. How thick should barriers be to safely stop a car that hits a barrier at 97 km/h?
7. ### Physics

Highway safety engineers build soft barriers so that cars hitting them will slow down at a soft rate. A person wearing a safety belt can withstand an acceleration of 300m/s^2. How thick should barriers be to safely stop a car that …
8. ### Physics

A person wearing a safety belt can withstand an acceleration of 300 m/s 2 . How thick should barriers be to safely stop a car that hits the barriers at 81.7 km/h?
9. ### Physics ASAP!!!

A person wearing a safety belt can withstand an acceleration of 300 m/s 2 . How thick should barriers be to safely stop a car that hits the barriers at 81.7 km/h?