Chapter 4, Problem 74A

a.

To determine

Average acceleration of dragster.

Answer to Problem 74A

Average acceleration of dragster is $44.57{\text{ m/sec}}^2$ .

Explanation of Solution

Given :

Mass of dragster $m=873\text{ kg}$

Initial velocity $u=0\text{ m/sec}$

Final velocity $v=26.3\text{ m/sec}$

Time taken to reach final velocity from initial velocity $t=0.59\text{ sec}$

Formula used :

According to first equation of motion,

  $v=u+at$

Where,

a is acceleration

t is time.

v is final velocity

u is initial velocity

Calculation:

Substitute the value of u, v and t in equation of motion.

  $\begin{array}{c}26.3=0+a\times 0.59\\ a=\frac{26.3}{0.59}\\ =44.57{\text{ m/sec}}^2\end{array}$

Conclusion:

Therefore, acceleration of dragster is $44.57{\text{ m/sec}}^2$ .

b.

To determine

Average force applied on dragster.

Answer to Problem 74A

Net average force on dragster is 38915.08 N.

Explanation of Solution

Given :

Mass of dragster $m=873\text{ kg}$

Initial velocity $u=0\text{ m/sec}$

Final velocity $v=26.3\text{ m/sec}$

Acceleration is $a=44.57{\text{ m/sec}}^2$

Time taken to reach final velocity from initial velocity $t=0.59\text{ sec}$

Formula used :

Force is given by,

  $F=ma$

Where,

m is mass

a is acceleration.

Calculation:

Substitute the values to find the net force on dragster.

  $\begin{array}{c}F=873\times 44.57\\ =38915.08\text{ N}\end{array}$

Conclusion:

Therefore, net average force on dragster is 38915.08 N.

c.

To determine

Horizontal force exerted by seat on the driver.

Answer to Problem 74A

Horizontal force applied by seat on driver is 3030.76 N.

Explanation of Solution

Given :

Mass of the driver $m=68\text{ kg}$

Initial velocity $u=0\text{ m/sec}$

Final velocity $v=26.3\text{ m/sec}$

Acceleration is $a=44.57{\text{ m/sec}}^2$

Formula used :

Force is given by,

  $F=ma$

Where,

m is mass

a is acceleration.

Calculation:

Substitute the values to find the horizontal force applied by seat on driver.

  $\begin{array}{c}F=68\times 44.57\\ =3030.76\text{ N}\end{array}$

So horizontal force applied by seat on driver is 3030.76 N.