Jul 23

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Jul 23

First, we need to calculate the initial kinetic energy of the car:

Initial kinetic energy = 0.5 * mass * velocity^2

Initial kinetic energy = 0.5 * 120kg * (5m/s)^2

Initial kinetic energy = 0.5 * 120kg * 25m^2/s^2

Initial kinetic energy = 1500 J

Next, we need to calculate the work done by the braking force to bring the car to rest:

Work done = force * distance

1500 J = force * 30m

force = 1500 J / 30m

force = 50 N

Now, we can calculate the average retardation:

Average retardation = (final velocity - initial velocity) / time

Since the car comes to rest, the final velocity is 0 m/s

Average retardation = (0 - 5m/s) / time

Average retardation = -5m/s / time

We also know that the distance traveled is equal to the average velocity multiplied by time:

Distance = average velocity * time

30m = (5m/s + 0) / 2 * time

30m = 2.5m/s * time

time = 30m / 2.5m/s

time = 12s

Now we can calculate the average retardation:

Average retardation = -5m/s / 12s

Average retardation = -0.4167 m/s^2

Therefore, the average retardation (braking acceleration or deceleration) is 0.4167 m/s^2 and the braking force is 50 N.

Initial kinetic energy = 0.5 * mass * velocity^2

Initial kinetic energy = 0.5 * 120kg * (5m/s)^2

Initial kinetic energy = 0.5 * 120kg * 25m^2/s^2

Initial kinetic energy = 1500 J

Next, we need to calculate the work done by the braking force to bring the car to rest:

Work done = force * distance

1500 J = force * 30m

force = 1500 J / 30m

force = 50 N

Now, we can calculate the average retardation:

Average retardation = (final velocity - initial velocity) / time

Since the car comes to rest, the final velocity is 0 m/s

Average retardation = (0 - 5m/s) / time

Average retardation = -5m/s / time

We also know that the distance traveled is equal to the average velocity multiplied by time:

Distance = average velocity * time

30m = (5m/s + 0) / 2 * time

30m = 2.5m/s * time

time = 30m / 2.5m/s

time = 12s

Now we can calculate the average retardation:

Average retardation = -5m/s / 12s

Average retardation = -0.4167 m/s^2

Therefore, the average retardation (braking acceleration or deceleration) is 0.4167 m/s^2 and the braking force is 50 N.

Google Gemini AI

Jul 23

Initial velocity, u = 5 m/s

Final velocity, v = 0 m/s

Distance, s = 30 m

Using the equation of motion:

v^2 = u^2 + 2as

0^2 = 5^2 + 2a - 30

a = -0.42 m/s^2

Therefore, the average retardation is

The braking force (F) is given by:

F = ma

where m is the mass of the car (120 kg) and a is the average retardation (0.42 m/s^2).

Therefore, the braking forces are:

F = 120 kg - 0.42 m/s^2