Problem Set

Chapter 3

Name______

Period______

  1. A human tissue cell has a diameter on the order of 1 μm. Estimate the number of cells in 1 cm3 of tissue.
  1. Solve the following problem. Express your answers in scientific notation.

1) 6.2x10-4m + 5.7x10-3m =

2) 8.7x108km - 3.4x107m =

3) (9.21x10-5cm)(1.83x108cm) =

4) 2.63x10-6m)/(4.08x106s) =

  1. If a cheetah can maintain a constant speed of 25 m/s, it will cover 25 meters every second. At this rate, how far will it travel in 10 seconds? In 1 minute?
  1. The speedometer of a car moving northward reads 60 km/h. It passes another car that travels southward at 60 km/h. Do both cars have the same speed? Do they have the same velocity? Explain your answers.
  1. Suppose a car moving in a straight line steadily increases its speed each second, first from 35 to 40km/h, then from 40 to 45 km/h, then from 45 to 50 km/h. What is its acceleration?
  1. In 5 seconds a car moving in a straight line increases its speed from 50 km/h to 65 km/h, while a truck goes from rest to 15 km/h in a straight line. Which undergoes greater acceleration? What is the acceleration of each vehicle?
  1. A space ship far from any star or planet experiences uniform acceleration from 65.0 m/s to 162.0 m/s in 10s . How far does it move?
  1. Killer whales at Sea World routinely jump 7.5 m above the water. What is their speed as they leave the water to achieve this?
  1. A hockey player glides along the ice at a constant speed of 1.25 m/s in the positive direction onto a rough section of ice, which slows him down. If he stops in 5.0 s, what is the magnitude and direction of his acceleration?
  1. True or False? Let us define the eastward direction as negative and the westward direction as positive. (a) If a car traveling eastward, its acceleration must be eastward. (b) If a car is slowing down, its acceleration may be positive. (c) A particle with constant nonzero acceleration can never stop and stay stopped.
  1. This is a graph of a toy car’s velocity. Describe the car’s velocity and average acceleration, as show in the graph.
  1. A particle is moving with a velocity of 60.0 m/s in the positive x-direction at t=0 s. Between t=0 and t=15.0 s the velocity decreases uniformly to zero. What is the acceleration during this 15.0 s interval? What is the significance of the sign of your answer?
  1. A bus that is traveling at 30.0 km/h speeds up at a constant rate of 3.5 m/s2. What velocity does it reach 6.8 s later?
  1. Joni jogs at a velocity of 2.50 m/s. If she then accelerates at a constant -0.10 m/s2, how fast will she be jogging when she has moved 10.0 m?
  1. A bike rider pedals with constant acceleration to reach a velocity of 7.5 m/s over a time of 4.5 s. During the period of acceleration, the bike’s displacement is 19 m. What was the initial velocity of the bike?
  1. A construction worker accidently drops a brick from a high scaffold. What is the velocity of the brick after 4.0 s?
  1. From the sample problem above, if you catch the coin at the same height as you released it, how much time did it spend in the air?
  2. A golf ball is released from rest at the top of a very tall building. Neglecting air resistance, calculate the position and the velocity of the ball after 1.00, 2.00, and 3.00 s.