Question

Car questions 1)A car with the mass of 200 kg moves with a speed of 2.00 m/s. If the car doubles it’s speed to 4.00 m/s then how much work was done on the car? A) 1200 JB) 100 JC) 400000 JD) 200 JE)1.00 J2)Given a car traveling on a flat road. If the mass of the car is 1000 kg and the velocity of the car is 3.00 m/s then what is the kinetic energy of the car? A) 0.0300 kj B) 157 kjC) 191 kjD) 4.50 kjE) 84.7 kj3) if a car has a mass of 500 kg and a velocity of 2.00 m/s. If the car increases it velocity to 4.00 m/s then it kinetic entertainment will do which of these?A) doubleB) tripleC) halveD)become one-fourth as muchE) quadruple

Answer 1

Given that the mass of the car is m = 200 kg

The initial speed of the car is

$v_o=\text{ 2 m/s}$

The final speed of the car is

$v_f=\text{ 4 m/s}$

We have to find the work done.

The work done can be calculated by the formula

$\begin{gathered} W=\text{ change in kinetic energy } \\ =\frac{1}{2}m(v_f)^2-\frac{1}{2}m(v_{_o})^2 \end{gathered}$

Substituting the values, the work done will be

$\begin{gathered} W=\frac{1}{2}\times200\times(4)^2-\frac{1}{2}\times200\times(2)^2 \\ =1600-400 \\ =1200\text{ J} \end{gathered}$

Thus, the work done will be 1200 J, the correct option is option A.