Acar traveling at +7.0 m/s accelerates at a rate of +0.80 m/s^2 for an interval of 2.0 s.find the vf

To solve this type of problem, the formula for linear-motion and acceleration will be used. The formula is stated below:

Vf = Vi + at

Where:

Vf = final velocity
Vi = initial velocity
a = acceleration
t = time

Substituting the given values into the equation:

Vf = 7 m/s + (0.8 ./s^2)*(2 s)
Vf = 8.6 m/s

Given:

The formula of VF is v=u+at

Coressponding to:

v= final velocity

 u= initial velocity which is 7m per second

a= acceleration which is 0.08m per second^2

t= time which is 2.0 seconds

 

Substitute: 

y=u+a

y=7+(0.80*2)

7+1.6=8.6 

VF=8.6 m/second^2

3,544.375Joules

Explanation:

Kinetic energy is the energy possessed by a body by virtue of its motion, It is expressed as;

Kinetic energy = 1/2mv²

m is the mass of the body

v is the velocity

For the ball carrier;

KE = 1/2(75)(6.5)²

KE = 3168.75/2

KE = 1584.375Joules

For the defender;

KE = 1/2(80)(7)²

KE = 3920/2

KE = 1960Joules

The kinetic energy of the ball carrier/defender system BEFORE the tackle = KE for the carrier + KE for the defender

kinetic energy of the ball carrier/defender system BEFORE the tackle= 1584.375+1960 = 3,544.375Joules