Answer to Question #217387 in Classical Mechanics for Help

Question

1) A 60.0-kg student runs at a constant velocity up a flight of stairs. If the vertical distance of the stairs is 3.2 m, the work done against gravity is ___x10^3 J 

Use the information below to answer the following 4 questions.

A 10.0-kg object is accelerated horizontally from rest to a velocity of 11.0 m/s in 5.00 s by a horizontal force.

2) The acceleration of the object is ___m/s²

3) The horizontal force given to the object is ___N

4) The distance travelled by the object is ___m.

5) The work done on the object is ___J.

Answer 1

$1)$

$\Delta h =3.2m$

$m = 60 kg$

$g = 9.8\frac{m}{s^2}$

$W = mg\Delta h = 60*9.8*3.2=1.88*10^3J$

$m_1= 10kg$

$v_0 = 0;v_1= 11\frac{m}{s}$

$t = 5s$

$2)$

$a = \frac{v_1-v_0}{t}= \frac{11-0}{5}=2.2\frac{m}{s^2}$

$3)$

$F = ma = 10*2.2 = 22 N$

$4)$

$s= v_0t +\frac{at^2}{2}= 0+\frac{2.2*25}{2}= 27.5m$

$5)$

$W_1 = Fs = 22*27.5 = 605J$

$\text{Answer:}$

$1)\text{...the work done against gravity is }1.88*10^3 J$

$\text{2) The acceleration of the object is }2.2m/s^2$

$\text{3) The horizontal force given to the object is }22N$

$\text{4) The distance travelled by the object is }27.5m$

$\text{5) The work done on the object is }605J$