A physics professor leaves her house and walks along the sid..

第1题

The acceleration of a bus is given by a(t) =α*t, where α = 1.2 m/s^3. If the bus's velocity at time t = 1.0s is 5.0 m/s, what is its velocity at time t = 2.0 s?

A、6.8 m/s

B、5.6 m/s

C、4.5 m/s

D、7.6 m/s

E、8 m/s

F、5 m/s

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第2题

The figure shows a position-versus-time graph of the motion of a car. Describe the velocity and acceleration during segments OA, AB, and BC. Which item is Not correct?

A、In segment OA, the velocity is positive and constant.

B、In segment OA, there is no acceleration.

C、In segment AB, the velocity is increasing.

D、In segment AB, there must be acceleration.

E、In segment BC, the velocity is not constant.

F、In segment BC, this velocity is greater in magnitude than the velocity in segment OA.

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第3题

A speeder traveling at a constant speed of 100 km/hr passes a waiting police car that immediately starts from rest and accelerates at a constant 2.5 m/s^2. How fast will the police car be traveling when it catches the speeder?

A、200 km/hr

B、210 km/hr

C、220 km/hr

D、190 km/hr

E、180 km/hr

F、230 km/hr

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第4题

The acceleration of a bus is given by a(t) =α*t, where α = 1.2 m/s^3. If the bus's position at time t = 1.0 s is 6.0 m, what is its position at time t = 2.0 s?

A、11.8 m

B、9.5 m

C、10 m

D、12.7 m

E、13.2 m

F、14.1 m

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第5题

Which of the following is a vector quantity:

A、Speed

B、time

C、acceleration

D、mass

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第6题

A physics professor leaves her house and walks along the sidewalk toward campus. After 5 min it starts to rain and she returns home. Her distance from her house as a function of time is shown in Fig. At Point _________( fill in the labeled points I/ II/ III/ IV/ V) is her velocity zero.

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第7题

The radial component of velocity for a particle moving in a circular path is____

A、A non-zero constant

B、Radius itself

C、Variable

D、Zero

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第8题

When acceleration is _______, a velocity of a particle is constant.

A、Constant but non zero

B、Maximum

C、Zero

D、None of these choices

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