Question

Jessie was driving her 2000-kg Camry when she dropped her phone. She leaned down to pick it up, and just then a small child rode his bicycle into the street 45 meters in front of her. She is traveling at 15 m/s (about 30 mph). She sees the boy and slams on the brakes, and the car comes to a stop with the bumper of the car just touching the tire of the bike. Whew!!

Calculate the braking force of the car.

A) 300 N
B) 4500 N
C) 6000 N
D) 9000 N

Answer 1

To calculate the braking force of the car, we can use Newton's second law of motion. By converting the initial velocity to km/h and calculating the acceleration, we can determine the force. In this case, the braking force is approximately 64,800 N.

Step-by-step explanation:

To calculate the braking force of the car, we need to use Newton's second law of motion which states that force is equal to mass multiplied by acceleration. In this case, the car comes to a stop, so the acceleration is the negative value of the initial velocity divided by the stopping distance.

First, we convert the car's initial velocity from m/s to km/h: 15 m/s = 15 * (3600/1000) km/h = 54 km/h.

Next, we calculate the acceleration: a = -v2 / (2 * d) = -542 / (2 * 45) = -32.4 m/s2.

Finally, we can use Newton's second law to calculate the force: F = m * a = 2000 kg * (-32.4 m/s2) = -64,800 N. Since force is a vector quantity, we take the magnitude of the force (ignoring the negative sign) to get 64,800 N.