physics

find distance on graph

( each segment in two diff parts) (delta x= 1/2( v0( velocity initial+ second velocity point times t ) lastly add the two solved segments together

ball directly up .. velocity and acceleration after leaving hand?

+,- ( acceleration negative because of gravity)

velocity and acceleration at top of motion?

0.- ( velocity because no motion, acceleration because of gravity)

Carl lewis once set a world record for the 100.0m run with a time of 9.86s. If after reaching the finish line, Mr. lewis walked directly back to his starting point in 90.9s, what is the magnitude of his average velocity for the entire tip?

0m/s because started and stopped in the same place.

when the outdoor emergency warning siren at chapels school was tested the sound from he siren took 7.0s to reach her house located 2.40 km from the school. What is the speed of the sound in the air?

2.4km/7.0s times 1000m/1km= 2400/7=342.857m/s

Which of the following situations is not possible?

A body travels with a constant velocity and a constant non-zero acceleration. This is because acceleration is the change in velocity

which one of the following constants must be met if the expression x= V0 + 1/2at^2 is to be used?

A is constant

New case: How long (in seconds) does it take the stone to hit the water?

Caculate using the x=x0+V0t+1/2(9.8)t^2 and then use quadratic equation ( last number will be negative)

How to find final velocity

Vf=Vi+at look at direction

how to find average acceleration?

Final velocity- initial velocity/ time

How long (in seconds) does it take the stone to hit the water?

Find t by using X= X0+V0t+1/2(9.8)t^2 ( x will be height)

A flea jumps straight up to a maximum height of some number. What is its initial velocity v0v0 as it leaves the ground?

Find velocity initial by using V^2- V0= 2a(x-x0) and solve.

What is the stone's velocity at t = some time? Keep 2 digits after the decimal point.

Find velocity with V= V0+ (a)(t) .... (v0=0)

What percentage of the takeoff velocity did the plane gain when it reached the midpoint of the runway?

First divide the length of the runway by 2. Next use the equation V2-V02= 2a(x-x0) to solve for v. Next divide the number you get by using that equation and the number you got above to solve for the percent.

How long does it take someone to cover the distance if they run half the distance and walk the other half?

First divide the run mph by 60. Then divide the walk mph by 60. Next divide by half of the distance for each one. Add those two numbers together.

average speed for rest of trip if you have the cars overall average speed?

First divide total time by 60. Next divide the first segment average speed by 60. The subtract total time from first segment average speed. Then take the number and divide by 60. Next multiply the number from the first total time division by the average mph for entire trip. Next put that number equal to average speed for the first length times the number for the first segment division plus v times the last division number. solve.

An object's initial velocity is some numberin the +x direction. It slows down with a constant acceleration whose magnitude is some number . After it reaches a momentary stop it reverses its direction of motion, to the -x, and speeds up with the same magnitude of the acceleration. What is its displacement (in meters) from the initial moment to tt =some number?

First find v using the equation v=V0+ at (acceleration is negative due to the reversing in direction) Next use equation x=x0 +1/2 ( V0+ v)(t) ( this will give you displacement)

Which of the following statements are correct?

If the average speed is zero, then the average velocity must be zero. The average speed can never be less than the magnitude of average velocity.

What is the speed vTOvTO of the plane as it takes off?

Solve for V... V= v0 + (a)(t) ... (v0=0)

How much time does it take the car to catch up with the truck (again, at a later time t)?

Solve for x and then use quadratic equation. X= X0+ V0t+1/2(a)(t)^2 ( make time negative for b on quadratic equation)

What is the distance dfirstdfirst traveled by the plane in the first second of its run?

Solve for x by using x=x0+v0t + 1/2(a)t^2

How long is the flea in the air from the time it jumps to the time it hits the ground?

Start by finding the up time. The equation you use is x=x0+1/2(V0+ V)t. Then you find the down time by using x=x0 +V0 +1/2(a)(t)^2. Then add the times together.

How long does it take someone to cover the distance if they run for half the time and walk the other half of the time.

Take the distance and put it equal to the both mph added together with x. Next solve for x. Once you have x times by 60. That gives you half the distance. Lastly times by 2 for the time.

find average speed?

Take the solution from the time it takes to cover the distance and divide by 60. Next take the distance and divide by the number you got above.

What is the distance dlastdlast traveled by the plane in the last second before taking off?

The first step is subtracting the time you got in part A -1. Next you solve for x using X= X0+ V0t + 1/2(a)(t)^2. Once you get the number from that equation you subtract the height/length from that and get the distance.

At t1t1 = some time an object's velocity is v1v1 = some number, and at t2t2 = some time its velocity is v2v2 = some time . Assuming a constant acceleration, What is its displacement (in meters) from t1 to t2?

The first step is to find the time by subtracting the two. Next use the equation x= xo+ 1/2 (v0+v)(t)

What are the positions of the car and the truck when they catch up in Part A?

The time you got for the car to catch up to the truck times the constant speed is the answer for both.

What are the Velocities of the car and the truck when they catch up in Part A?

The trucks speed is constant so number given in problem is the velocity, the cars velocity use equation v=V0+ (a)(t)

t t1t1 = some time an object's velocity is v1v1 = some time to the EAST, and at t2t2 = some time its velocity is v2v2 = some timeto the WEST. Assuming a constant acceleration, Take EAST as the positive direction. What is its acceleration with a proper sign?

To find acceleration rearrange equation. v=v0 + at to solve for a. v will be a negative number.

What is the maximum height above the ground?

Use x= x0 +1/2(v0+v)t (v=number in problem) ( time is the stones higher point time)

A plane accelerates from rest at a constant rate of some number along a runway that is some number long. Assume that the plane reaches the required takeoff velocity at the end of the runway. What is the time tTOtTO needed to take off?

Use x= x0+v0t+ 1/2(a)(t^2) (x will be the runway length and you will solve for t)

How long (in seconds) does it take the stone to reach the highest point? Keep 3 digits after the decimal point.

V= Vot+at ( divide velocity by acceleration)

For which of the following situations will the path length equal the magnitude of displacement?

a ball is rolling down on an inclined plane

Velocity differs from speed in that velocity indicates a particle's __________ of motion.

direction

Once you have selected a coordinate system, you can express a two dimensional vector using a pair of quantities known collectively as

components

Speed differs from velocity in the same way that __________ differs from displacement.

distance

The position x of an object is given by the equation x= A +Bt+Ct^2, where t refers to time. What are the dimensions of A, B,C?

distance, distance/time, distance/time^2

on a graph when is acceleration positive?

going up

A vector has, by definition, both __________ and direction.

magnitude

Something moves down and stops what is velocity and acceleration before it stops but after button is pushed.

negative, and positive (velocity negative because downward)

The__ of the particle at point A differs as expressed in one coordinate system compared to the other but the __ from A to B is the same as expressed in both coordinates

position, displacement

average acceleration of a particle over time?( one segment)

second velocity minus first velocity divided by second time - origin ( starting point)

Find instantaneous acceleration?

second velocity minus starting point divided by the time around the time given.

find amin?

slope of flat line on the graph

how to find amax?

slope= y2-y1/x2-x1 ( first section of graph)

scalar quantity

speed, distance

How to find average speed in miles per hour

take second time and divide by 60. Then times that number by the miles per hour. Next subtract the miles away from the number above. Lastly divide that number by 1/6 to get the answer.

vector quantity

velocity, displacement, position, acceleration, average velocity

In which of the following situations does a car have a westward acceleration?

the car travels eastward and slows down

An object's initial velocity is some number and it speeds up with a constant acceleration whose magnitude is some number. What is its velocity after a displacement of some number?

v^2= v0+2a(x-x0) solve ( no time in problem so use this equation to solve for velocity)

Unlike speed, velocity is a __________ quantity.

vector

Find the maximum height ymaxymax reached by the rocket. Ignore air resistance and assume a constant free-fall acceleration equal to 9.80 m/s2m/s2 .

x= x0+ v0t +1/2at^2 solve for height v=v0+at for velocity then use v2-v02=2a(x-x0) and solve

An object's initial velocity is blank (number) and it speeds up with a constant acceleration whose magnitude is blank(number). What is its displacement (in meters) from the initial moment to tt = number ?

x=x0+V0t +1/2(a)(t)^2 vi/v0= initial velocity a= acceleration t= time looking for x = displacement plug in numbers and solve