Question

Mark sees a crushed soda can on the ground. He kicks it fiercely with a velocity of 12m/s at projected angle of 36°. What is the highest point that the soda can reaches? Sin 36 degrees equals 0.866. 2. A 5000 kg. freight train traveling at speed of 28 m/s strikes an identical car at rest. If they stick

Answer 1

Solution.

$1. v_0=12ms^{-1};$

$\alpha =36^o;$

$h_{max}-?;$

$v=0ms^{-1};$

$v_{0y}=v_0\sdot sin \alpha;$ $v_{0y}=12ms^{-1}\sdot0.866=10.392ms^{-1};$

$h_{max}=\dfrac{v_y^2-v_{0y}^2}{2g};$

$h_{max}=\dfrac{0m^2s^{-2}-108m^2s^{-2}}{-2\sdot9.8ms^{-2}}=5.51m$ ;

$2. m=5000kg;$

$v_1=28ms^{-1};$

$v_2=0ms^{-1};$

$m_1=m_2=m;$

$mv_1+mv_2=(m_1+m_2)v_F$ ;

$v_F=\dfrac{mv_1+mv_2}{m_1+m_2};$

$v_F=\dfrac{5000kg\sdot28ms^{-1}+5000kg\sdot0ms^{-1}}{5000kg+5000kg}=14ms^{-1};$

Answer: $1. h_{max}=5.51m; 2. v_F=14ms^{-1}.$