Kinematic Definition and 395 Threads

Homework Statement a) Show that for a given velocity V_0 a projectile can reach the same range R from two different angles \theta = 45 + \delta and \theta = 45 - \delta, as long as R doesn't go over the maximum range R_{max} = \frac{V_0^2}{g}. Calculate \delta in function of V_0 and R. b)...

There is a problem in my Physics textbook which says: Homework Statement "A car runs counter-clockwise in a circular lane of 1 km of diameter, going through the south extreme at 60 km/h on the instant t = 0. From that point onwards, the driver accelerates the car uniformely, reaching 240 km/h...

Hello guys. i know i shouldn't be doing this, but I am asking you if you can help me with a problem for my younger sister, because my major is something else (biology, genetics) and she need this and doesn't know how to solve it.. 1. Homework Statement At an upper end of the slope inclined at...

Homework Statement Serving at a speed of 170 km/h a tennis player hits the ball at a height of 2.5 m and an angle θ below the horizontal. The service line is 11.9 m from the net, which is 0.91 m high. What is the angle θ such that the ball just crosses the net? Will the ball land in the service...

1. The problem statement of my lab I have this physics lab where I have to find the maximum velocity and maximum acceleration of a high school student sprinting/running using carbon tape and a spark timer. Which I already did. Now I'm having trouble developing my sources of error section. I hope...

Homework Statement "A body dropped from the top of a tower covers a distance '7x' in the last second of its journey where 'x' is the distance covered in the first second. How much time does it take to reach the ground ?" Homework Equations ## S = ut - \frac{1}{2}gt^2## The Attempt at a...

Homework Statement 2. Homework Equations [/B] Consider a particle that is described by $$x(t)=(2.0-0.1t) \cos(0.5t)$$ and $$y(t)=(2.0-0.1t) \sin(0.5t)$$ t in seconds and x,y in meters. In previous subquestions we were asked to determine an expression for the module of the velocity vector and...

Homework Statement At t = 0, one toy car is set rolling on a straight track with initial position 16.0 cm, initial velocity -3.7 cm/s, and constant acceleration 2.90 cm/s2. At the same moment, another toy car is set rolling on an adjacent track with initial position 10.0 cm, an initial velocity...

Homework Statement A body travels 200 cm, in the first 2 sec,and 220 cm in the next 4 sec What will be the velocity at the end of seventh second from the start ? Homework Equations ##v_{avg}=\frac {Δx} {Δt}## 3. The attempt at a solutio...

<Mentor's note: moved from a technical forum, therefore no template> My teacher made this question: Iceman is sliding down a 10.0 x 10^(-8) nm ice that is inclined at 20.0 degrees with respect to the horizontal. Iceman is initially at rest. The coefficient of kinetic friction between iceman's...

Homework Statement Homework EquationsThe Attempt at a Solution So (i) was easy enough and I got a time of 0.67 seconds. For (ii), since the horizontal time is 0.67 seconds this means the TOTAL time spent in air is also 0.67 seconds, so to calculate max height we split this time in half...

Homework Statement Max (65 kg) pushes Toni (50 kg) with a force of 360 N. The force of friction is 0 on Toni and 80 on Max. (a) Find each girls acceleration (b) If Max pushes Toni for 0.1 s, how far will Toni travel in 0.5 s? Homework Equations Fnet=ma v2=v1+at d=v1(t)+1/2a(t)^2 The Attempt...

Homework Statement "In part 2 of the lab you will be firing a water balloon over a tall fence, aiming to hit a target." The fence is 3 meters high. You may fire the balloon from anywhere behind the fence, up to 4 meters away from it: the target will be 20 meters away. Find the angle to shoot...

Homework Statement A mass M falls under gravity (force mg) through a liquid with decreasing viscosity so that the retarding force is -2mv/(1+t). If it starts from rest, what is the speed, acceleration, and distance fallen at time t=1. Homework Equations F=ma The Attempt at a Solution F =...

Homework Statement A car moving due south at 20.0 m/s enters a highway cloverleaf. The car will exit the cloverleaf to merge with westbound traffic traveling at 29.0 m/s. The time between entering the cloverleaf and exiting to merge with westbound traffic is 20.7 s. What is the magnitude of...

Homework Statement a spool of radius R1 and R2 (R2>R1) is kept on hortizontal surface. A force f= 2t N (where t is time ) acts on the inner radius tagentially find the angular momentum of the system about the bottomost point of the spool. Homework Equations v=u+at W=Wi+alpha(t) L=IW+mvrThe...

Homework Statement Find the equation of motion of the object by setting the derivative of the total energy equal to zero. Homework Equations r(theta)=(Rcos(theta), Rsin(theta), q*theta) v(theta)=dr/dt=(-Rsin(theta)dtheta/dt, Rcos(theta)dtheta/dt, q*dtheta/dt) derivative of Total Energy =...

Homework Statement Find the angle at which the projectile is launched. (Hint: use tan^2+1=sec^2) Initial Net Velocity=430 m/s The projectile lands perfectly on the edge of a cliff 80 meters high and 175 meters away. Homework Equations tan^2+1=sec^2 Kinematics, i.e.- v=vo+gt...

Homework Statement An 8.5 gram slug is fired East from a 0.357 magnum hand gun held 1.5 meters above the ground. The muzzle velocity (as the projectile leaves the gun) is 1400 ft/sec. The bullet is accelerated at a constant rate as it travels through the 10 cm long barrel. After leaving the...

Homework Statement In the mechanism shown below, the angular velocity of link 2 is 17 rad/s CW, constant. Find the angular velocity (magnitude and direction) of link 3. The distance between A and C is 109 mm, the length of link 3 is 125 mm, and θ= 111°. Note: B is a pin-slider In the...

Homework Statement A student in the back row of class fires a pea shooter in an attempt to hit the blackboard. The student fires it a distance of 23m from his seat to hit the black board. The pea hits the board after 1.4 seconds at a location 9.3 meters below the ceiling. The pea is fired from...

I understand most of the kinematic equations, but there is just this one equation that omits time from the equation. I always end up with V02+2a(x - x0) = 2V0V + V2 The 2V0V part is what I don't understand how to get rid of. So if you please could you do the equation with steps , I would be...

Homework Statement The acceleration of a particular car during braking has magnitude bt, where t is the time in seconds from the instant the car begins braking, and b = 2.2 m/s3 .If the car has an initial speed of 60 m/s , how far does it travel before it stops?Homework Equations : [/B] I know...

Homework Statement Homework Equations Formulas for a_r and a_theta. The Attempt at a Solution I got the second derative of r but I think the fluxie v is a mistake. I am sure that \dot{v} =a\ , right?

Homework Statement A car accelerates at 1.95m/s2 along a straight road. It passes two marks that are 28.0m apart at times t=3.95s and t=5.20s. What was the car's velocity at t=0? Homework EquationsThe Attempt at a Solution t1=3.95s, t2=5.20s, d=28m, t=t12-t1=1.25s, a=1.95m/s2 v0=...

Why 's' in all kinematics equation is displacement. S = Ut + ½a t^2 , v^2 = u^2 + 2aS is it because S in v = dS/dt is a small distance , very small distance and we treat it as a position of particle at a time t1 during Δt→0 and its direction is from t1(intial position) to t2(final...

Homework Statement Concept Simulation 2.3 provides some background for this problem. A ball is thrown vertically upward, which is the positive direction. A little later it returns to its point of release. The ball is in the air for a total time of 8.21 s. What is its initial velocity? Neglect...

Well, the problem says: From some height a object with mass m is thrown . Determinate the law that describes how the velocity of fall v changes, if on the object, besides gravity, acts the force air resistance, which is proportional to velocity v (the proportionality coefficient is k), ie must...

I am having a great difficulty in plotting, understanding & visualising the graphs, which is important aspect in physics. So I want some help from everyone to please show me, how to understand a given graph better & juice out everything which it wants. I want to make my fundamental strong by...

A mass m1 is on a frictionless surface. To its right is a second mass m2 not touching the ground, but in the air. An applied force is applied towards the right of both masses. What is the minimum force needed so that the second object JUST starts to slip downwards...

wrobel submitted a new PF Insights post Rare Kinematic Formula Continue reading the Original PF Insights Post.

In the no v kinematic equation, $x={x}_{o}+{v}_{o}t+a{t}^{2}/2$, why do you have to solve $a{t}^{2}/2$ first before solving down completely?

What is the best way to remember the four kinematic equations and what they mean and when you apply them? Thank you.

Homework Statement Andrew is driving his van to deliver groceries in Elmvale. As he travels along Hwy 92, a fox stops on the road. Andrew is traveling at 75 km/h and is 42 m away from the fox when he applies his brakes. It takes him 3.4 s to stop. a) How far did Andrew travel before stopping...

Homework Statement A student is testing the kinematic equations for uniformly accelerated motion by measuring the time it takes for light-weight plastic balls to fall to the floor from a height of 3 m in the lab. The student predicts the time to fall using g as 9.80 m/s^2, but finds the...

Homework Statement Homework Equations relevant equations are listed with each question The Attempt at a Solution 25. ** Displacement = 131 km (South) Average velocity = total displacement / total time Average velocity = 131 km (S) / 2.0 h Average velocity = 65.5 km /h (south) 26. **...

Hi, I'm trying to implement an auto track guidance system for ground vehicles (Eg Tractors), I'm using Matlab and Simulink. I'm at a point where I can calculate heading errors. I'm not too sure how to calculate the lateral errors. Also, I need help in designing the controller. I'm using...

I have been trying to calculate the distances to the spiral arms (neutral Hydrogen clouds) and our equation seems to work perfectly for longitudes 0<l<90 but doesn't seem to work for the outer galaxy (i.e. between 90<l<270) - we get distances but they're not correct. After reading a lot of...

Homework Statement Driving along a steady speed of 26m/s and suddenly see a child 150m from you. Breaks can produce acceleration of -2.5m/s² but it takes time to get the foot from the gas to the brake pedal. How much time do you have, if to avoid hitting the child? Known: d=150m a=-2.5m/s²...

Driving along a steady speed of 26m/s and suddenly see a child 150m from you. Breaks can produce acceleration of -2.5m/s^2 but it takes time to get the foot from the gas to the brake pedal. How much time do you have, if to avoid hitting the child?

Hello forum, The kinematic equations for motion with constant acceleration are: v_f = v_0 + a*t x_f = x_0 + v_0 * t +(0.5) a*t^2 The acceleration a is a constant. Is it possible to use them if the acceleration is not constant but a function of time? For example, a(t)= 3t^2+2? Can we simply...

Homework Statement I was told that kinematic viscosity depends on pressure , but not dynamic viscosity Homework EquationsThe Attempt at a Solution in my opinion, the dynamic viscosity depends on pressure , since it's formula is μ = tau / (du/dy) , where tau is the stress . and stress can be...

A car travels around a circular track with a radius of r=250m. When it is at point A then VA=5m/s which increases at a rate of a=(0.06t)m/s2. Determine the magnitude of its velocity and its acceleration when it is 1/3 around the track. My distance in this situation is obviously 524m. Can anyone...

Hello Forum, the kinematic equations for motion with constant acceleration are vector equations which can each be expanded into 3 scalar (or component equations). The vector equations are: v_f = v_0 + a (Delta_t) r_f = r_0 + v_0 (Delta_t) + (0.5) a (Delta_t)^2 r_f = r_0 + (0.5) (v_f + v_0)...

Homework Statement MECHANICS: Given Theta, L, M, and acceleration of elevator relative to ground. Find the time it takes for the block to reach the end of the incline. Here is a diagram: http://k-elahian.com/tmp/nip.PNG Homework Equations f=ma kinematics relative acceleration The Attempt...

Homework Statement We call Kinetic energy Ec=1/2 mv^2 its deferral into the work integral gives: \begin{align*} w_{12}&=\int\limits_1^2\delta W\\ & = \int\limits_1^2 \vec F \wedge d\vec r\\ &\underbrace{=\int\limits_1^2dE_c}_{why?} \end{align*} But Why does the kinematic energy appears in...

Homework Statement Some tornado researchers see a faraway tornado moving straight toward them. They see a bolt of lightning from the cloud above the tornado and 20 seconds later hear thunder. Exactly 40 seconds after seeing the first lightning , they sees second bolt and hear the sound thunder...

1. A space vehicle accelerates uniformly from 85 m/s at t=0s to 462 m/s at t=10s. What is avg acceleration? How far did the space vehicle move from t=2s to t=6s. 2. Got the avg accel easily enough w basic equation for accel. Problem is conceptual with the displacement portion of the question...

Hello, I am a first year science teacher doing my best with teaching physics for the first time (my degree is chemistry but I am in a very small school). I am teaching projectile motion. I was creating a worksheet and trying to solve a problem I made up when I realized something wasn't working...

Homework Statement A skater jumps off a quarterpipe ramp and reaches 5m over the ramp. We can assume that he jumps in a vertical line. Find the speed the skater had before jumping off the ramp. Homework Equations https://www.physicsforums.com/threads/introductory-physics-formulary.110015/ All...