Question

How long (time) must a group of people pull with a force of 600N on a stalled 1500kg car to give it a velocity of 1.5m/s?Report your answer to the nearest hundredth.

Answer 1

Answer:

3.75 seconds

Explanation:

The change in momentum is equal to the force times time. So, we can write the following equation:

$\begin{gathered} F\cdot t=\Delta p \\ F\cdot t=mv_f-m_{}v_i \end{gathered}$

Where F is the force, t is the time, m is the mass, vf is the final velocity and vi is the initial velocity.

Since the initial velocity is 0 m/s, we can simplify the equation and solve the equation for t as follows

$\begin{gathered} F\cdot t=mv_f-m(0) \\ F\cdot t=mv_f \\ t=\frac{mv_f}{F}_{} \end{gathered}$

So, replacing m = 1500 kg, vf = 1.5 m/s and F = 600N, we get

$t=\frac{1500\operatorname{kg}(1.5\text{ m/s)}}{600N}=\frac{2250\text{ kg m/s}}{600\text{ N}}=3.75\text{ s}$

Therefore, the answer is 3.75 seconds.