Answer:
14 seconds
Explanation:
Distance covered by sports car is measured with 21*t where t is time.
Distance covered by police is measured with at^2/2(t-time, a-acceleration) as it doesnt have starting velocity. If the distances are equal(police catches sport car)
then we have 21t=3/2*t^2 Solving this equation we get t=14 & t=0;
excluding the starting point we have 14 seconds
Answer:
Approximately
, assuming that the acceleration of this ball is constant during the descent.
Explanation:
Assume that the acceleration of this ball,
, is constant during the entire descent.
Let
denote the displacement of this ball and let
denote the duration of the descent. The SUVAT equation
would apply.
Rearrange this equation to find an expression for the acceleration,
, of this ball:
.
Note that
and
in this question. Thus:
.
Let
denote the mass of this ball. By Newton's Second Law of Motion, if the acceleration of this ball is
, the net external force on this ball would be
.
Since
and
, the net external force on this ball would be:
.
9514 1404 393
Answer:
- moderate low: 82
- moderate high: 112.75
- vigorous low: 123
- vigorous high: 174.25
Explanation:
When calculations are repetitive, I find it convenient to use a calculator that can work with tables.
The PMHR is (220 -15) = 205.
Each of the other heart rates is computed as the formula shows. For example, the low moderate heart rate is 205×0.40 = <u> 82 </u> bpm
The other rates are shown in the attached table. They are computed the same way.
Answer:
Work done, W = 750 joules
Explanation:
It is given that,
Force acting on the object, F = 50 N
It moves to a distance of, d = 15 meters
We need to find the work done on an object. We know that the product of force and distance covered is called the work done. As the force and the displacement are in same direction. So,


W = 750 joules
So, the work done on an object is 750 joules. Hence, this is the required solution.