A car comes to a bridge during a storm and finds the bridge washed out. The driv

Question

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 22.7 m above the river, whereas the opposite side is a mere 1.5 m above the river. The river itself is a raging torrent 64.0 m wide.

Part A

How fast should the car be traveling just as it leaves the cliff in order to just clear the river and land safely on the opposite side?

Part B

What is the speed of the car just before it lands safely on the other side?

Explanation / Answer

here,

the width of the river , R = 64 m

height difference , h = 22.7 - 1.5

h = 21.2 m

(a)

let the initial speed of car be u

time of light , t = sqrt(2*h/g)

t = sqrt(2*21.2 /9.8)

t = 2.08 s

u*t = R

u * 2.08 = 64

u = 30.77 m/s

the car be traveling at 30.77 m/s just as it leaves the cliff in order to just clear the river and land safely on the opposite side

(b)

final vertical velocity , vy = g*t,

vy = 9.8 * 2.08

vy = 20.38 m/s

the final velocity , v = sqrt(u^2 + vy^2)

v = sqrt(30.77^2 + 20.38^2)

v = 36.91 m/s

the speed of the car just before it lands safely on the other side is 36.91 m/s

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