Kinematics problem with constant acceleration

Thread starter livestrong136
Start date May 16, 2012
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Acceleration Constant Constant acceleration Kinematics Kinematics problem

In summary, kinematics is the branch of physics that deals with the motion of objects without considering the forces that cause the motion. Constant acceleration is when an object's velocity changes at a constant rate and its acceleration remains the same throughout its motion. To solve a kinematics problem with constant acceleration, one can use the equations of motion. The units of acceleration are typically meters per second squared (m/s²) in the SI system of units. The sign of acceleration in a kinematics problem depends on the direction of the velocity and the chosen coordinate system, with positive acceleration indicating an object is speeding up and negative acceleration indicating an object is slowing down.

May 16, 2012

livestrong136

A ball is thrown downwards from a top of a 20m building with an initial velocity of 15m/s. What equation could be used to model its height?

My answer: h (t) = -4.9t²-15t+20

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May 16, 2012

Doc Al

Mentor

livestrong136 said:

My answer: h (t) = -4.9t²-15t+20

Looks good to me.

What is kinematics?

Kinematics is the branch of physics that deals with the motion of objects without considering the forces that cause the motion.

What is constant acceleration?

Constant acceleration is when an object's velocity changes at a constant rate. This means that the object's acceleration remains the same throughout its motion.

How do you solve a kinematics problem with constant acceleration?

To solve a kinematics problem with constant acceleration, you can use the equations of motion: v = u + at (final velocity equals initial velocity plus acceleration multiplied by time), s = ut + 1/2at² (displacement equals initial velocity multiplied by time plus half of acceleration multiplied by time squared), and v² = u² + 2as (final velocity squared equals initial velocity squared plus twice the acceleration multiplied by displacement).

What are the units of acceleration?

The units of acceleration are typically meters per second squared (m/s²) in the SI system of units. Other common units include feet per second squared (ft/s²) and kilometers per hour squared (km/h²).

How do you know if the acceleration is positive or negative in a kinematics problem?

The sign of acceleration depends on the direction of the velocity and the chosen coordinate system. If the object is speeding up in the positive direction, the acceleration is positive. If the object is slowing down in the positive direction, the acceleration is negative. Similarly, if the object is speeding up in the negative direction, the acceleration is negative. If the object is slowing down in the negative direction, the acceleration is positive.