The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. Velocity is equivalent to a specification of an object's speed and direction of motion (e.g. 60 km/h to the north). Velocity is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of bodies.
Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The scalar absolute value (magnitude) of velocity is called speed, being a coherent derived unit whose quantity is measured in the SI (metric system) as metres per second (m/s or m⋅s−1). For example, "5 metres per second" is a scalar, whereas "5 metres per second east" is a vector. If there is a change in speed, direction or both, then the object has a changing velocity and is said to be undergoing an acceleration.
Homework Statement
A car with a velocity of 25 m/s [E] changes its velocity to 25 m/s [S] in 15s. Calculate the car's average acceleration.Homework Equations
a = v/t
The Attempt at a Solution
The problem I'm having with this question (And actually, vectors in general) is the direction in the...
A 50.0 g Super Ball traveling at 27.0 m/s bounces off a brick wall and rebounds at 15.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 4.50 ms, what is the magnitude of the average acceleration of the ball during this time interval?
I can't seem to get...
Hey everyone,
I'm taking AP Physics B and self-studying AP Physics C this year. School hasn't started yet, but I am already stuck on this problem from Fundamentals of Physics by Halliday, Resnick, & Walker.
Homework Statement
A tennis ball is dropped onto the floor from a height of...
Homework Statement
A motorboat starting from a dead stop accelerates at an average rate of 2.0 m/s^2 for 3 seconds, then very rapidly roars up to 4.0m/s^2 for 4 seconds. Finally, it decelerates to a stop 20 seconds later at a rate of 1.1m/s^2.
(a) What is its average acceleration during the...
[b]1. Six dogs, each having a mass of 32 kg, pull a 325 kg sled horizontally across ice. If each dog applies a force of 86 N [fwd], what average acceleration es the sled experience? Assume that friction is negligible.
Equation:
F=ma
My solution:
6 x 86 N= 516 N
F=ma
a= F/m
a=...
Homework Statement
Calculate the average acceleration of a non-uniform cylinder (large can of tomato soup) down an inclined plane.
Homework Equations
What equation should I use?
The Attempt at a Solution
I think the equation I should use is d=vt+0.5at^2, but I am not sure. If I...
Homework Statement
A sprinter has a velocity of 6.0m/s [s] at t=3.0s.
Five seconds later he is moving north with a speed of 4.0m/s. calculate the sprinters average acceleration
Homework Equations
average acceleration=change in velocity/elapsed time
The Attempt at a Solution...
Homework Statement
A 45.0 g Super Ball traveling at 30.0 m/s bounces off a brick wall and rebounds at 21m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.0ms, what is the magnitude of the average acceleration of the ball during this time interval? (It...
So here is the question I'm stuck on.
A woman is reported to have fallen 112 ft from a building, landing on a metal ventilator box, which she crushed to a depth of 24 in. She suffered only minor injuries.
Calculate the magnitude of her average acceleration while in contact with the box...
A dragster and a driver together have mas 930.1 kg. the dragster, starting from rest, attains a speed of 25.8 m/s in .56 s. Find the average accel. of the dragster during ths time interval. What is the size of the average force on the dragster during this time interval? Answer in units of N...
Suzie (of mass 52kg) is roller blading down the sidewalk going 36 mph. She notices a group of workers down the walkway who have unexpectedly blocked her path, and she makes a quick stop in 1.9 seconds. What is Suzies average acceleration? Answer in m/s^2. What force was exerted to stop Suzie...
Homework Statement
Secretariat ran the Kentucky derby with time for the quarter mile of 25.2s, 24s, 23.8s, and 23s. Assuming that secretariat's instantaneous speed at the finish line was the same as the average speed during the final quarter mile, find his average acceleration for the entire...
Hi! I am new here and can't for the life of me figure out what I am doing wrong solving this problem, if someone could help that would be great!
QUESTION:
A bird takes 8.5 s to fly from position A (va= 4.4 m/s (31 ° S of E) to position B(vb= 7.8 m/s ( 25° N of E) along the path. Find the...
Well I posted this in the calculus section but think it would be answered easier here since it's mild calculus if any.
1. Homework Statement
I'm studying for a Calculus test and I am having trouble on a problem. And who better to ask than the members of physicsforums!?
Basically, we are...
At one instant a bicyclist is 30 m due east of a park's flagpole, going due south with a speed of 18 m/s. Then, 14 s later, the cyclist is 45 m due north of the flagpole, going due east with a speed of 9 m/s. For the cyclist in this 14 s interval, find each of the following.
A)average...
Help please :)
Homework Statement
A Car with a velocity of 25m/s[E] changes its velocity to 25m/s[S] in 15s. Calc. the car's average acceleration.
Homework Equations
Aav= Vf - Vi / T
The Attempt at a Solution
I know that the angle is = to 45 degrees S of W since it's a...
A golf ball released from a height of 1.76 m above a concrete floor, bounces back to a height of 0.80 m. If the ball is in contact with the floor for 4.62 ms, what is the magnitude of the average acceleration a of the ball while it is in contact with the floor?
4.9x^2-1.76
I used this...
Homework Statement
An astronaut has left spacelab V to test a new space scooter for possible use in constructing Space Habitat I. Her partner measures the following velocity changes, each taking a place in a 10-s interval. What are the magnitude, the algebraic sign and and the direction of the...
Homework Statement
Okay here's the problem, The coordinate of an object is given as a function of time by x = 4t^2 - 3t^3, where v is in m/s and t is in seconds. Its average acceleration over the interval form t = 0 to t = 2
I wast told the answer is -10m/s^2 but i can't figure out how...
was wondering which formula I would use to solve this equation...
a car traveling in a straight line has a velocity of +5.0m/s at some instant.
After 4.0seconds, it velocity is +8.0m/s. What is it average acceleration in this time interval?
A bird takes 8.5s to fly from position A to Position B along a path (looks like a parabolic curve facing downward) determine the birds average acceleration
Va = 4.4 m/s [31 S of E]
Vb = 7.8 m/s [25 N of E]
Hi, this may seem like a silly question, but I'm gunna ask it anyway...
I have the ff. data for acceleration:
0
9.152
8.43
9.07
7.731
10.423
When I calculate the average acceleration, would it be the sum divided by 6 or would it be the sum divided by 5? That is, should I include...
A rocket blasts off and moves straight upward from the launch pad with constant acceleration. After 2.6 s the rocket is at a height of 80.0 m.
(a) What is the acceleration of the rocket?
______m/s2
(b) What is its speed at this time?
______m/s
Hello, I have been stumped on this question...
Here's my question:
An object has a speed of 18 m/s at a certain time, and 2.4 seconds later, it's speed is 30 m/s in the opposite direction.
So my question is, what were the magnitude and direction of the average acceleration of the object during this 2.4 second time period? And, if you give...
A 50.7 g superball traveling at 25.1 m/s bounces off a brick wall and rebounds at 22.8 m/s. A high speed camera records this event. If the ball is in contact with the wall for 3.5 ms, what is the magnitude of the average acceleration of the ball during this time period?
Unfortunately I'm...
A bird takes 8.5s to fly from position A to Position B. Determine the birds average acceleration.
Velocity A = 4.4 m/s [31 Degrees S of E]
Velocity B = 7.8 m/s [25 Degrees N of E]
QUESTION=
a bird takes 8.5 s to fly from position A to position B along the path. determine the bird's average acceleration.
va= 4.4 m/s (3 degrees S of E) -- is this the initial velocity?
vb= 7.8 m/s ( 25 degrees N of E) -- is this the final velocity?
THIS IS WHAT I GOT SO...
I'm suppossed to find the average acceleration of the mass during the time interval from -t to t.
The formula I'm using is a(-t,t)=\frac{(v(t)-v(-t))}{(t-(-t))}
I've already derived v(t) and v(-t) but I'm not sure how to simplify them after subtracting them.
v(t)=-R\omega sin(\omega...
I've been killing myself over this problem because I cannot figure it out. Can someone please help me?
A tennis ball with a velocity of 40.0 m/s to the right is thrown perpendicularly at a wall. After striking the wall, the ball rebounds in the opposite direction with a velocity of -8 m/s...
Hello everyone. I am having a little trouble with this problem and I was wondering if you could give me a hand with it.
A car traveling 85 km/h strikes a tree. The front end of the car compresses and the driver comes to rest after traveling 0.80 m. What was the average acceleration of the...
This question is all qualitative, but I don't know what centripetal and average acceleration is around a circle. The question is about two runners on a circular track, Runner A on the inside lane, Runner B on the outside lane. The runners have the same SPEED, I think that runner A has a larger...
A ball is dropped from 4 ft and rebounds back to 3 feet. If the ball was in contact with the ground for 0.01 seconds, then what is the average acceleration of the ball during contact? The answer on the back of the book is 3000 ft/sec^2. So average acceleration is defined as \frac{\Delta...
A jet plane is cruising at 300 m/s when suddenly the pilot turns the engines up to full throttle. After traveling 4.0 km, the jet is moving with a speed of 400 m/s.What is the jet's acceleration, assuming it to be a constant acceleration?
first i converted 4km to m. then i said that since at...
A 747 airliner reaches its takeoff speed of 173 mi/h in 35.2s. What is the magnitude of its average acceleration?
(77.3341 m/s)/(35.2 s) = 2.20 m/s^2
I am wondering did I do it correctly?
I'm stuck on this rather simple problem...
A golf ball released from a height of 1.4 m above a concrete floor bounces back to a height of 1.2 m. If the ball is in contact with the floor for .62 ms what is the average acceleration of the ball whil ein contact with the floor.
I know that...
Hello, I'm starting to study physics, and I have a problem that I have puzzled me for long... here it is. any help appreciated. thanks in advanced.
A tennis ball with a speed of 23.6 m/s is
thrown perpendicularly at a wall. After strik-
ing the wall, the ball rebounds in the opposite...
A piston-engine dragster set a world record by starting from rest and hitting a top speed of 244 mi/h over a measured track of 440 yd. Compute its average acceleration in m/s^2.
I assumed the acceleration to be constant in order to find t using this formula : v_av = 1/2(v_i + v_f).
After...
Can the average acceleration of a body be not equal to the instantaneous acceleration for at least an instant?
I know the answer to the question above is NO. But I find the answer; using Mean value theorem in calculus.
Let me know if there is any answer based on physics.
Thanks
A sports car is advertised to be able to stop in a distance of 44 m from a speed of 95 km/h. What is its [average] acceleration in m/s2? How many g's is this (g = 9.80 m/s2)?
I have 7.9 m/s2, as my answer for average acceleration, but webassign isn't accepting my answer. Can someone help me out?
Help ...
I need help with these problems and anyone who can respond to these asap... it would be very much apprciated... so here they are I am so confused please help me...
1.) what is the magnitude of the average acceleration of a skier who starting from rest reaches a speed of 5.5m/s when...
The problems reads, A carnival Ferris wheel has a 14.2m radius and completes one revolution about its horizontal axis in 10.1s. Consider the time interval from the instant when a passenger is at the lowest point of the uniform circular motion to a clock reading 5.05 seconds later. What was the...