Explanation:
There are 5 kinematic equations, and 5 variables.
Each question will give you 3 variables and ask you to solve for a fourth.
To determine which equation to use, look at which variable is <em>not</em> included in the problem.
For example, if the question does not include time, then you need to use a kinematic equation that does not have t in it. That would be:
v² = v₀² + 2aΔx
Or, if the question does not include the final velocity, then you need a kinematic equation that does not have v in it. That would be:
Δx = v₀ t + ½ at²
Answer:
(a) the runner's kinetic energy at the given instant is 308 J
(b) the kinetic energy increased by a factor of 4.
Explanation:
Given;
mass of the runner, m = 64.1 kg
speed of the runner, u = 3.10 m/s
(a) the kinetic energy of the runner at this instant is calculated as;
(b) when the runner doubles his speed, his final kinetic energy is calculated as;
the change in the kinetic energy is calculated as;
Thus, the kinetic energy increased by a factor of 4.
Answer:
-140
Explanation:
A gas loses 80joules of heat.
The gas also does 60 joules of work
Therefore the change in internal energy can be calculated as follows
= -80 + (-60)
= -80-60
= -140
Hence the change in internal energy is -140
Explanation:
initial velocity 0, final velocity 8.00,time taken 2×60= 120+50=170,now using formula a=v_u\t=8.00-0/170=8.00/170=