Physics I Test I

If the initial position is (40 meters, southwest) of the origin. and the final position is (50 meters, northeast) of the origin. what is me displacement? Note) Southwest is exactly halfway between so. and west and northeast is exactly halfway between north and east

(90 meters, northeast)

What is the magnitude of a unit vector?

1

rank the following pairs of forces according to the magnitude of the net force,with the largest magnitude net force at the top and the smallest at the bottom.

1.) (4.0 N,right) and (4.0 N,right) 2.)(4.0N,left) and (4.0 N,up) 3.)(4.0 N,right) and (4.0 N,left)

A bicycle wheel has an angular speed of 30 rad/s. Rank the linear speed of a point on the tire with the largest value at the top and the smallest value at the bottom.

1.) Old-fashioned high-wheel 2.) Adult mountain bike 3.) Child bicycle

rank the following pairs of forces according to the magnitude of the gravitational force,with the smallest magnitude at the top and the largest at the bottom.

1.) m^1=5m,m^2=5m 2.) m^1=8m,m^2=6m 3.)m^1=5m,m^2=10m 4.)m^1=7m,m^2=8m

Rank the following according to the magnitude of the gravitational force, with the smallest magnitude at the top an the largest at the bottom. Assume that the two masses are constant.

1.)r=4R 2.)r=2R 3.)r=R

An object traveling along the x-axis hes a velocity of 2.0 m/s from 0 to 9.0 s, 0 m/s from 4.0 to 6.0 s, -2.0 m/s from 6.0 to 8.0 s, and 4.0 m/s from 8.0 to 10 s. Whet Is the average velocity of the object from 0 to 10 s?

1.2 m/s

An object is dropped from a height of 10 m above the floor. Approx. how fast is it going just before it hits the floor?

14 m/s

Suppose you own a cylindrical water tank with radius r and height h. You one day decide to build a new tank with double the radius and half the height of the original tank. What is the ratio of the volume of the new tank to the original tank?

2

The x component of a vector is 3 N, and its y component is 4 N. What is its magnitude?

5 N

Select all of the following that are vectors.

90 N,up and 90 N, north

Objects A a. B both move with constant acceleration along the ieaxis. Object A has a velocity of 10 m/s antl an acceleration of 0 m/s' when It imams object 13, which Is rest at Me origin at t= 0 s. If object 13 has an acceleration of nee antl starts moving the instant object A gasses Mgkh object crosses the enIsh line 90,100 in first?

A and B cross the finish line at the same time.

Vectors A,B and C are shown in the diagram. What are the values of the y

A^y >0, B^y <0, C^y >0

What does the word net imply when determining net force?

Addition

Select all statements that a true for an object in free-fall

Air resistance is negligibly small. The gravitational pull is approx. constant. The gravitational force acts on the object.

For projectile motion, how is the angle of elevation defined?

Angle of the initial velocity above the horizontal

A man moves a heavy cabinet across a floor by pushing it, as shown*. What is the direction of the normal force acting on the cabinet caused by the floor?

B

Identical boxes are at rest on six planes inclined different angles. Rank the planes (denoted by timir incline angles) according to the Matt friction force the plane exerti on Me box with the largest friction force on Me top a. the smallest on the bottom. The coeff clents of StatiC friction are I for A a. F, Mr B and E, and 2 for C and D.

E , C , A , D , B , F

A stone Is thrown from the ground at an angle to the horizon.' and falls back. the ground. A graph of the vertical component of its velocity versus time Is shown. Select all points on the graph that correspond to the stone traveling downward.

E , D

A box weighing 400 N lying on a horizontal surface is pushed by a 200 N horizontal force. The box is just on the point of slipping. What is the coefficient of static friction?

Equal to 0.5

In which situations do long-range forces apply?

Every situation.

True or False: Motion can be understood without analyzing forces.

False.

A crate with a child sitting on top of it being pulled to the right with a force F across a horizontal floor. Both the child and the crate are going to the right at a constant speed. For each of the forces in the left column, match the object upon which the interaction partner acts.

Gravitational force on the child - Earth Contact force on the child - Crate Contact force on the top surface of the crate -Child Contact force on the bottom surface of the crate - Floor

Which fundamental forces have the longest range?

Gravity and Electromagnetism

During each time interval on a motion diagram, the magnitudes of the displacements are increasing. If the object is moving in the positive x-direction, then what is the acceleration?

In the positive x-direction

A wheel is spinning around Its center at 30 rocas arid el point on its outer edge is moving of 6 m/s. !Me angular speed of the wheel is increased, then what will happen to the linear speed of the point on Os outer edge,

It will increase.

A car moving to the right is sliding to a halt. Select the correct description of the force of friction.

Kinetic friction to the left

A car travels around a circular track counterclockwise (as from above) When the car is located at the east end of the circle, what is the direction of its velocity?

North

A heavy crate of mass M is being lifted up at a constant speed by applying a force F, as shown*. Which rope has the least amount of tension? Assume that the pulleys and ropes are ideal.

Rope 2.

If the force F1-2 corresponds to the gravitational force exerted on an object 2 by object 1, then what must F2-1 have?

Same Magnitude and opposite direction.

Select all of the following effects that are caused by nonzero radial acceleration

The direction of the objects velocity changes. The object moves around a circle.

The trajectory of an object Is shown. Select all of the following that explain why the range and the horizontal displacement are unequal.

The initial and Final vertical positions are unequal. The range includes only the part of the trajectory for which the vertical displacement is equal to zero.

A car is stopped at a stop sign when a driver of a large truck not seeing the stop sign slams into the car from behind. Which one of the statements is true?

The magnitude of the force exerted by the truck on the car is the same as the magnitude of the force exerted by the car on the truck.

What is G in the equation F=G m^1m^2/r^2 ?

The universal gravitational constant. Value of 6.674*10^-11

True or False: The tension in an ideal cord in equilibrium is always the same at every location song the cord.

True.

Selects all of the following statements that are true.

Two forces can describe the interaction between two objects. A force is a push or pull.

Which of the following equations correctly relates the weight W of an object to its mass m?

W=mg

The sum of the internal forces on a system always equal to what?

Zero

A child slides down a snow-covered hill,as shown. Which of the vectors shown is closest to the direction of gravitational force exerted by the Earth on the Child?

a. the gravitational force always points towards the center of the Earth.

For projectile motion, with the +y axis up, match the component in the left column with the right section

a^x - 0 m/s^2 a^y - -9.8 m/s^2 v^x - Constant v^y - Decreasing

The net force acting on an object over a time interval is shown by the net force versus time graph In the Image. The object was moving In the positive A-direction at lime t. At which time Is the object's speed a maximum,

t^2

Consider vector A in two dimensions. Its magnitude is A and theta is the angle the vector makes with the positive x axis. Which of the following expressions is equal to theta?

tan^-1 (A^y/A^x)

A box is sliding down an inclined surface. What is the magnitude of the friction force on the box?

μ^kN