156k views
0 votes
The bus, at location A, is traveling at 30 m/s when it is shifted to neutral and allowed to

coast. Find the speed of the bus at location B. **Hint: Let location B be o potential

energy. h is the height above this point.

User Chif
by
4.9k points

1 Answer

3 votes

Complete Question

The complete question is shown on the first uploaded image

Answer:

The velocity of the bus at B is
v_B= 31.6\ m/s

Step-by-step explanation:

Let's take position B as base point .

From the diagram height between point B and A ia mathematically evaluated as


h_A = 60 -55


h_A = 5 \ m

From the question we are told that

The velocity at location A is
v_A = 30 m/s

According the law of conservation of energy


PE_A + KE_A = KE_B

Where
PE_A is the potential energy at A which is mathematically represented as


PE_A = mgh_A


KE_A is the kinetic energy energy at A which is mathematically represented as


KE_A = (1)/(2) mv^2_A


KE_B is the kinetic energy at A which is mathematically represented as


KE_B = (1)/(2) mv_B^2

Where
v_B is the velocity at location B

So


mgh_A + (1)/(2) mv_A^2 = (1)/(2) mv_B^2

Making
v_B the subject of the formula


v_B= \sqrt{(gh_A + (1)/(2) v_A^2 )/(0.5) }

Substituting values


v_B= \sqrt{((9.8 * 5) + (1)/(2) 30^2 )/(0.5) }


v_B= 31.6\ m/s

The bus, at location A, is traveling at 30 m/s when it is shifted to neutral and allowed-example-1
User Steverino
by
6.0k points