Problems 1D 2D Motion PDF

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PHY 2053 Rahman Section Sample problems on 1D and 2D Motion 1. The motions of a car and a truck along a straight road are represented by the velocity-time graphs below. The two vehicles are initially alongside each other at time t = 0.

At time T, what is true of the distances traveled by the vehicles since time t = 0? A) They will have traveled the same distance. B) The truck will not have moved. C) The car will have traveled farther than the truck. D) The truck will have traveled farther than the car. E) There is not enough information to determine since this is a plot of velocity, not distance. 2. You walk 40 m to the north. You then turn 60° to your right, so that you are facing 30° north of east, and walk another 45 m. How far are you from where you originally started? A) 43 m B) 60 m C) 74 m D) 82 m E) 102 m

3. Which of the following situations is impossible? A) An object has instantaneous velocity directed east and acceleration directed west. B) An object has instantaneous velocity directed east and acceleration directed east. C) An object has instantaneous velocity of zero, but non-zero acceleration. D) An object has constant non-zero acceleration and changing velocity. E) An object has constant non-zero velocity and changing acceleration.

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4. When a ball is thrown straight up, the acceleration at its highest point A) is upward B) is downward C) is zero D) reverses from upward to downward E) reverses from downward to upward 5. A racing car accelerates uniformly from rest along a straight track. This track has markers spaced at equal distances along it from the start, as shown in the figure. The car reaches a speed of 140 km/h as it passes marker 2.

Where on the track was the car when it was traveling at half this speed that is at 70 km/h? Hint: First use the information you have to calculate the acceleration (make up a distance to Marker 2). A) Before marker 1 B) At marker 1 C) Between marker 1 and marker 2

6. A skydiver’s velocity is constant due to air resistance on her parachute. After this occurs, the magnitude of the drag force on the parachute is A) equal to the force of gravity acting on the skydiver. B) is much smaller than the force of gravity acting on the skydiver. C) is slightly smaller than the force of gravity acting on the skydiver. D) is greater than the force of gravity acting on the skydiver. E) zero. 7. Two bullets are fired simultaneously horizontally over level ground. The bullets have different masses and different initial velocities. Assume air resistance is negligible. Which one will hit the ground first? A) the fastest one B) the slowest one C) the heaviest one D) the lightest one E) They strike the ground at the same time.

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8. A cat leaps to try to catch a bird. If the cat's jump was at an angle 60° above the horizontal and its initial velocity was what is the highest point of its trajectory, neglecting air resistance? A) 0.29 m B) 0.58 m C) 10.96 m D) 0.19 m

9. A stalled car is being pushed up a hill by three people, and it is moving at a constant speed. The net force on the car is A) zero. B) in the same direction of the car's motion. C) in the opposite direction of the car's motion. D) at an angle relative to the hill. E) None of the above 10. A child standing on a bridge throws a rock straight up. It rises for a time and then falls down to the river below. The rock leaves the child's hand at time t = 0 s. If we take upward as the positive direction, which of the graphs shown below best represents the acceleration of the stone as a function of time?

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11. A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. A stopwatch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.3 s. What is the height of the cliff if air resistance is negligibly small? A) 22 m B) 43 m C) 77 m D) 91 m E) 134 m

12. A tennis ball is thrown upward at an angle from point A. It follows a parabolic trajectory and hits the ground at point D. At the instant shown, the ball is at point B. Point C represents the highest position of the ball above the ground.

While in flight, how do the x and y components of the velocity vector of the ball compare at the points B and C? A) The x components are the same at B and C; the y component has a larger magnitude at C than at B. B) The velocity components are non-zero at B and zero at C. C) The x component is larger at C than at B; the y component at B points up while at C, it points downward. D) The x component is larger at B than at C; the y component at B points down while at C, it points upward. E) The x components are the same at B and C; the y component at C is zero m/s.

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