It takes 164 kJ of work to accelerate a car from 23.7 m/s to 27.8 m/s. What is the car's mass?
I tried using this equation but it didn't work
KE = 1/2mv^2
Work done equals the CHANGE in K.E.
Have you tried this:
(1/2)m*[27.8^2 - 23.7^2] = 164,000 ?
Solve for m. It should work.
An antelope moving with constant acceleration covers the distance between two points 70.0
m apart in 7.00 s. Its speed as it passes the second point is 15.0 m/s. (a) What is its speed at the first
point? (b) What is its acceleration?
To solve this problem, we can start by using the equation for kinetic energy (KE):
KE = 1/2 * m * v^2,
where KE is the kinetic energy, m is the mass of the object, and v is the velocity.
In this case, we are given the change in kinetic energy (work) and the initial and final velocities. The work is given as 164 kJ (kilojoules), the initial velocity is 23.7 m/s, and the final velocity is 27.8 m/s.
The equation for work (W) is given by the formula:
W = ΔKE = KE_final - KE_initial.
Substituting the given values, we have:
164 kJ = 1/2 * m * (27.8^2 - 23.7^2).
Now we can solve for the mass (m). First, let's calculate the difference in the squares of the velocities:
(27.8^2 - 23.7^2) = 772.84 - 561.69 = 211.15.
Now, we can substitute this value into the equation for work:
164 kJ = 1/2 * m * 211.15.
To solve for m, we can rearrange the equation:
2 * 164 kJ / 211.15 = m.
Now, let's calculate this value:
2 * 164 kJ / 211.15 = 328 / 211.15 ≈ 1.55 kg.
Therefore, the mass of the car is approximately 1.55 kg.