I can't answer this question without a figure. I've found a similar problem as shown in the first picture attached. When adding vectors, you don't have to add the magnitudes only, because vectors also have to factor in the directions. To find the resultant vector C, connect the end tails of the individual vectors.
<em>The red line (second picture) represents the vector C.</em>
The formula for calculating <em>density </em>is P=M/V where P is the <em>density</em>, M is the <em>mass</em>, and V is the <em>volume</em>.
The problem gives you the <em>mass</em>, 30g, and the <em>volume</em>, 60cm^3;you can plug those into the equation, which should give you P=30/60.
Your answer should end up being P=0.5 g/cm^3.
WORK:
P=M/V
P=30g/60cm^3
P=0.5g/cm^3
Answer is: <span>1/4 its old kinetic energy .
</span>V₁ = 10 m/s.
V₂ = 5 m/s.
m₁ = m₂ = m.
E₁ = 1/2 · m₁ · V₁², E₁ = 1/2 · m · (10 m/s)² = 50 · m.
E₂ = 1/2 · m₂ · V₂², E₂ = 1/2 · m · (5 m/s)² = 12,5 · m.
E₂/E₁ = 12,5m / 50m = 0,25.
V - speed of semi-truck.
m - mass of semi-truck.
E - kinetic energy of semi-truck.
Answer: 100 N
Explanation: Taking into account the second Newton Law the total force applied to any system is equal to the mass *acceleration.In this case the crate moves at constant speed so the accelaration is zero. In order to satisfy this fact, the friction force must be equal the applied force of 100 N .
