During a storm, a car traveling on a level horizontal road comes upon a bridge that has washed out. The driver must get to the other side, so he decides to try leaping the river with his car. The side of the road the car is on is 21.9 m above the river, while the opposite side is only 1.8 m above the river. The river itself is a raging torrent 58.0 m wide.

A) How fast should the car be traveling at the time it leaves the road in order just to clear the river and land safely on the opposite side?
B) What is the speed of the car just before it lands on the other side?

1. 👍
2. 👎
3. 👁
1. hf=hi+vi*time-4.9t^2
1.8=21.9+vi*t-4.9t^2

and
58=vi*t

solve for t in the second equation
t=58/vi
put that in the first equation, solve for vi

Now, speed just before impact
vertical speed=9.8*t
speedtotal=sqrt(vi^2+verticalspd^2)

1. 👍
2. 👎
2. Bob seems to be using vi both for vertical and horizontal speed

I think in fact the original vertical speed is zero so
h = Hi + 0 -4.9 t^2
1.8 = 21.9 - 4.9 t^2
t^2 = 4.1
t = 2.03 seconds to fall

now the car has to go horizontal
58 meters in 2.03 seconds
so I will call the constant horizontal speed u
where
u = 58/2.03 = 28.6 m/s

then
speed = sqrt (28.6^2 + v^2)
where v = 0 + 9.81*2.03
v = 19.9 m/s
so
speed at landing = 34.9 m/s

by the way, that car is toast due to the 35 m/s vertical speed at landing

1. 👍
2. 👎

## Similar Questions

1. ### phys

A car comes to a bridge during a storm and finds the bridge washed out. The driver must get to the other side, so he decides to try leaping it with his car. The side the car is on is 20.2 m above the river, while the opposite side

2. ### physics

An automobile traveling 95 overtakes a 1.10--long train traveling in the same direction on a track parallel to the road. Q1: If the train's speed is 75 , how long does it take the car to pass it Q2:How far will the car have

3. ### Physics

A car moves on a level horizontal road in a circle of radius 30.5 m. the coefficient of friction between the tires and the road is 0.5. The maximum speed with which the car can round this curve without slipping is:

4. ### Physics

A 10,000N car comes to a bridge during a storm and finds the bridge washed out. The 650-N driver must get to the other side, so he decides to try leaping it with his car. The side the car is on is 16.6 m above the river, while the

1. ### Physics

A car is traveling on a level horizontal rode comes to a bridge during a storm and finds the bridge washed out. The driver must get to the other side, so he decides to try leaping it with his car. The side of the road the car is

2. ### Math

A car travels along a straight road, heading east for 1 h, then traveling for 30 min on another road that leads northeast. If the car has maintained a constant speed of 48 mi/h, how far is it from its starting position? Round your

3. ### Physics

A car comes to a bridge during a storm and finds the bridge washed out. The driver must get to the other side, so he decides to try leaping it with his car. The side the car is on is 19.5m above the river, while the opposite side

4. ### Physics

A car can decelerate at -2.47-m/s2 without skidding when coming to rest on a level road. What would its deceleration (in m/s2) be if the road is inclined at 8.7o and the car moves uphill? (Assume the same static friction

1. ### Physics

A tow truck pulls a car from rest onto a level road. The tow truck exerts a horizontal force of 1500 N on the car. The frictional force on the car is 810 N. Calculate the work done by each of the following forces on the car as the

2. ### physics

A car is traveling at 45.0 mi/h on a horizontal highway. (a) If the coefficient of static friction between road and tires on a rainy day is 0.100, what is the minimum distance in which the car will stop? ____ m (b) What is the

3. ### Physics

A car traveling at 50 km/h hits a bridge abutment. A passenger in the car moves forward a distance of 74 cm (with respect to the road) while being brought to rest by an inflated air bag. What magnitude of force (assumed constant)

4. ### Calculus 1

A police car is located 60ft to the side of a straight road. A red car is driving in the direction of the police car and is 90 ft up the road from the location of the police car. The police radar read that the distance between the