0
Kinematics
Kinematics is the study of how a body moves. This includes linear motion, angular motion, and rotational motion.
3,459 Questions
What is the minimum speed to drive at a 70 mph?
In most countries, on most roads, there is no specified minimum speed.
What limits a vehicle's top speed?
Vehicle speed is limited by a combination of engine horse-power, transmission configuration (gear ratios), tire size and type, aerodynamics and, in rear-wheel drive vehicles, differential ratios. Once the engine has reached the peak of it's horse-power, top speed can be increased by changing one of the other variables. Also, improving intake & exhaust systems or altering the suspension can also increase the vehicle's top-end.
First summarise what we know as equations and values.
Call the initial velocity of the ball vi. This is the value we need to calculate.
We know:
The final velocity of the ball vf = 0m.s-1. It has completely stopped at the top of its travel. (We are not interested in the trip down.)
The deceleration of the ball is caused by gravity (discounting air friction) which is 9.81m.s-2. So the acceleration a = -9.81m.s-2. It is negative because it is acting in the opposite direction to the initial movement of the ball.
The distance travelled by the ball before it comes to a stop at the top is d = 3m.
So we have: vf, a and d, and we need an equation with these and vi that we can arrange to solve for vi.
We know from basic kinematic equations that:
# vf = vi + a.t # d = vi.t + 1/2.a.t2
but these require the time value t which we do not know.
However, because we have two equations, we can solve one for t to eliminate it:
rearranging Equation 1 to solve for t gives us:
# t = (vf - vi)/ a and we can substitute this into Equation 2 and, after some rearranging to solve for vi, which is the value we want, get:
vi = the square root of (vf2 - 2.a.d)
So putting in the values gives us:
vi = the square root of (02 - 2 . -9.81 . 3)
= the square root of ( - 2 . -9.81 . 3)
= the square root of ( - 6 . -9.81 )
= the square root of ( 58.86)
= 7.67
= 7.7m.s-1
according to the equation for potential energy of a body i.e.''mgh'' if mass of the body is halved m/2 keeping it hight same then its energy will become half as well...
How do you find the uniform acceleration if the speed and acceleration are given?
Find out the time using speed and acceleration, (time=speed/acceleration) and then use it to find out uniform velocity. From that find out uniform acceleration. (as uniform acceleration is equal changes of velocity over equal intervals of time)
Why do all the dreams you have take place in the house you grew up in?
Answer:In particular, to see your childhood home or a home that you no longer live in, suggests your own desires for building a family. It also reflects aspects of yourself that were prominent or developed during the time you lived in that home. You may experience some feelings or unfinished expression of emotions that are now being triggered by a waking situation.
What does the area underneath a velocity-time curve represent?
Mathematically, the area underneath the graph of a curve is the value you get by integrating that curve. From classical mechanics, one knows that the integral of an object's velocity with respect to time gives you that object's position as a function of time. Thus, the area underneath the velocity time graph from one point in time to another is the change in position of that object between those two times or, it's distance traveled.
Can a position time graph have negative slope?
yes, if the speed is negative, that is, moving backward
State any one factor which determines the kinetic energy of a body?
One factor affecting the kinetic energy of a particle (or body) in is the viscosity of the medium through which that particle moves
Which of this two quantities is not a vector quantity magnetic field or charge?
Charge is not a vector.
It depends on how thick the Kevlar vest is.
Ek = 1/2*m*v^2, where Ek is kinetic energy, m is mass, and v is velocity. Therefore, 1/2*20*2^2 = 40 Joules.
The formula Ek =1/2*m*v^2 can be used for any point mass, that is, a mass that is small enough that it can be considered to have all its mass in one point, or a solid object that is not rotating.
Mass has no effect on torque. Torque is the product of distance (from the axis), force, and an angular function. Mass can, however, make the turbine more stable - it will take longer to react to variations in wind. More mass will increase the MOMENT OF INERTIA (rotational inertia).
How long will it take an object that falls from rest to attain a velocity of 147 m sec?
The formula is vf = v0 + at
It means that the (final velocity) is equal to the (initial velocity) plus (acceleration multiplied by elapsed time). We can rearrange the equation to look like
t = (vf - v0) / a
Since initial velocity is zero, and we are assuming that Earth has acceleration due to gravity of 9.8 m/s2, we can sub the values into the equation and get
t = (147 m/s) / (9.8 m/s2)
t = 15 s
So it will take 15 seconds
No because u let the energy out of you, you dount save it.
There are a few ways to go about solving this one. Here's one that takes a few steps, but they're easy to follow. What is the average speed of the car during its rapid deceleration? Assuming constant deceleration, it's (80 - 0)/2 = 40 km/s = 11.1 m/s. (I'm playing fast and loose with the signs at this point.) Divide the stopping distance (50 m) by that speed and you get 4.5 seconds. Acceleration, a, is delta V / delta t = -22.2 / 4.5 = -4.9 m/s2. Since the acceleration of gravity is -9.8 m/s2, the deceleration of the car is about half a g. Note that deceleration is the same as negative acceleration.
What are similarities between a catapult and joint?
the similarities between a catapult and a joint are that both spring backwards and forwards in a certain motion and path. for example, the elbow springs forwrds and backwards whilst doing exercise, and the great catapult fires its long arm forwards with the contents of the top flung forwards, the arm then taken back .
The similarites are that they both work under the physics principles of levers. The elbow, for instance, is a Class I lever when you extend it and works the same way as a counterweight trebuchet. Another example based on levers is the knee. When you extend it, it works on the same principle as a traction trebuchet which is a Class III lever.
If it accelerates from 75 m/s to 145 m/s at a uniform rate, then its average speed during
the acceleration is 0.5(145+75) = 110 m/s.
Distance covered in 15 sec at average speed of 110 m/s = (15 x 110) = 1,650 m = 1.65 km.
How are horsepower and thrust related in a jet aircraft?
The more horsepower you have, the more thrust you will be able to produce. The more horsepower you have, the more thrust you will be able to produce.
