Physics 110- Pre-Lecture Assignment 1

In a carnival game you roll a ball up a ramp and into a basket. During one attempt, you roll the ball so that it has a velocity of 6.0 m/s i^ at the bottom of the ramp and 2.0 m/s i^ at the top (where i^ points up the ramp). If it takes 1.5 s for the ball to roll from the bottom to the top of the ramp, the ball's average acceleration is ______ m/s2 i^.

-2.7

At a soccer practice, the players run sprints. They start at the goal, run 10 m toward the center of the field and then run back to the goal. Then they run 20 m toward the center of the field and back to the goal. Finally they run 30 m toward the center of the field, turn around, and run back to the goal again. One player times herself to try and beat her personal best time. She runs the first 10 m in 2.5 s and gets back to the goal in 2.8 s. Then she runs the 20-m sprint in 5.7 s and gets back to the goal in 6.7 s. She runs the final 30-m sprint in 12 s and gets back to the goal in 15 s. What was her average velocity for the entire exercise? 3.0 m/s 0 m/s 2.5 m/s 2.7 m/s

0 m/s

In the calculation of the area of a rectangle with dimensions of 4.282 m by 0.050 m, which of the following answers has the correct number of significant figures? 0.214 m2 0.21 m2 0.2141 m2 0.2 m2

0.21 m2

A driver parked his car on a steep hill and forgot to set the emergency brake. As a result, the car rolled down the hill and crashed into a parked truck. If the car was moving at 10 mph (4.5 m/s) when it hit the truck 7.0 seconds after it began to move, what was the car's average acceleration while it rolled down the hill? Define the positive x direction to be down the hill. -0.6 m/s2 i^ -1.4 m/s2 i^ 0.6 m/s2 i^1 .6 m/s2 i^ -1.6 m/s2 i^ 1.4 m/s2 i^

0.6 m/s2 i^1

You toss a ball straight up by giving it an initial upward velocity of 18 m/s. What is the velocity of the ball 0.50 s after you released it? Define the positive y direction to be upward, the direction that you toss the ball. 9.0 m/s j^ 13 m/s j^ -23 m/s j^ -13 m/s j^ -9.0 m/s j^ 23 m/s j^

13 m/s j^

At a soccer practice, the players run sprints. They start at the goal, run 10 m toward the center of the field and then run back to the goal. Then they run 20 m toward the center of the field and back to the goal. Finally they run 30 m toward the center of the field, turn around, and run back to the goal again. One player times herself to try and beat her personal best time. She runs the first 10 m in 2.5 s and gets back to the goal in 2.8 s. Then she runs the 20-m sprint in 5.7 s and gets back to the goal in 6.7 s. She runs the final 30-m sprint in 12 s and gets back to the goal in 15 s. What was her average speed for the entire exercise? 0 m/s 2.7 m/s 2.5 m/s 3.0 m/s

2.7 m/s

The radius of the Earth is 6,380. What is the radius in cm? 6.38 × 10^2 cm 6.38 × 10^5 cm 6.38 × 10^-2 cm 6.38 × 10^4 cm 6.38 × 10^8 cm

6.38 × 108 cm

Which of the following best describes how to calculate the average acceleration of any object? Average acceleration is always halfway between the initial acceleration of an object and its final acceleration. Average acceleration is always equal to the change in speed of an object divided by the time interval. Average acceleration is always equal to the displacement of an object divided by the time interval. Average acceleration is always equal to the change in velocity of an object divided by the time interval.

Average acceleration is always equal to the change in velocity of an object divided by the time interval.

The SI base unit for mass is the: Gram Pound Newton Slug Kilogram

Kilogram

Suppose you are hiking along a trail. Make a comparison between the magnitude of your displacement and your distance traveled. The magnitude of your displacement must be less than your distance traveled. The magnitude of your displacement can be less than your distance traveled. The magnitude of your displacement must be greater than your distance traveled. The magnitude of your displacement can be greater than your distance traveled. The magnitude of your displacement must be equal to your distance traveled. The magnitude of your displacement can be equal to your distance traveled.

The magnitude of your displacement can be less than your distance traveled. The magnitude of your displacement can be equal to your distance traveled.

On a straight road, a car speeds up at a constant rate from rest to 20 m/s over a 5 second interval and a truck slows at a constant rate from 20 m/s to a complete stop over a 10 second interval. How does the distance traveled by the truck compare to that of the car? The truck travels half as far as the car. The truck travels twice as far as the car. There is not enough information to answer the question. The truck travels the same distance as the car.

The truck travels twice as far as the car.

Which of the following best describes the acceleration of a bungee jumper during free fall? negative zero positive constant

constant

In the equation z = ct + d, z is measured in meters and t is measured in seconds. What are the dimensions (units) of d? s/m m m/s s m·s

m

In the equation z = ct + d, z is measured in meters and t is measured in seconds. What are the dimensions (units) of c? s m·s m/s m s/m

m/s