A tow truck pulls a car from rest onto a level road. The tow truck exerts a horizontal force of 1500 N on the car. The frictional force on the car is 810 N. Calculate the work done by each of the following forces on the car as the car moves forward 12 m:
(a) the force of the tow truck on the car
(b) the force of friction
(c) the normal force
(d) the force of gravity
I just need help with c and d because I don't understand how you can find the fg and FN without knowing the mass of the car
the forces in c and d are normal (perpendicular) to the direction of motion of the car
they do no work
Well, finding the mass of the car is definitely important to calculate the force of gravity (Fg) and the normal force (FN). Since we don't have that information, let's assume that the car has a mass of 1000 kg. Keep in mind that these calculations will be approximations, but should give you a general idea.
(a) The work done by the force of the tow truck on the car is given by the formula: work = force x distance. In this case, the distance moved is 12 m and the force exerted by the tow truck is 1500 N. So, the work done by the force of the tow truck is: 1500 N x 12 m = 18,000 J.
(b) The work done by the force of friction can be calculated using the same formula: work = force x distance. The distance moved is still 12 m, but in this case, the force of friction is given as 810 N. So, the work done by the force of friction is: 810 N x 12 m = 9,720 J.
(c) The normal force (FN) is the force exerted by a surface to support the weight of an object resting on it. In this case, it would be equal to the force of gravity acting on the car (Fg) in the vertical direction. Assuming the mass of the car is 1000 kg, we can calculate the force of gravity using the formula: Fg = mass x gravity. Assuming the acceleration due to gravity is approximately 9.8 m/s^2, we get: Fg = 1000 kg x 9.8 m/s^2 = 9,800 N. Therefore, the normal force is also 9,800 N.
(d) The force of gravity (Fg) is the weight of the car, which we've approximated to be 9,800 N (assuming a mass of 1000 kg).
Keep in mind that these calculations are based on the assumption of a 1000 kg mass for the car. If you have the actual mass of the car, be sure to use that for a more accurate answer.
To calculate the work done by the force of gravity and the normal force, you are correct that you need to know the mass of the car. However, in this case, you haven't been given the mass of the car, so you cannot directly calculate the work done by these forces.
The force of gravity, also known as the weight, can be calculated using the equation:
Fg = m * g
Where Fg is the force of gravity, m is the mass of the car, and g is the acceleration due to gravity (approximately 9.8 m/s^2 on Earth). Without knowing the mass, you cannot calculate the force of gravity or the work done by it.
Similarly, the normal force, denoted as FN, is the perpendicular force exerted by a surface to support the weight of an object resting on it. It is equal in magnitude and opposite in direction to the force of gravity when an object is on a level surface. The normal force can also be calculated using the equation:
FN = Fg
Again, without knowing the mass of the car, you cannot directly calculate the normal force or the work done by it.
Therefore, in this scenario, you can only calculate the work done by the force of the tow truck (a) and the force of friction (b).
To calculate the work done by the forces, you'll need to determine the displacement of the car. Given that the car moves forward a distance of 12 m, you can proceed with the calculations.
(c) To find the normal force (FN), you need to consider that the car is on a level road. On a level road, the normal force is equal to the gravitational force acting on the car. This means that the normal force is equal to the weight of the car. The formula for weight is:
Weight (W) = mass (m) × acceleration due to gravity (g)
However, since you don't have the mass of the car, you cannot determine the exact value of the normal force. If you are provided with additional information regarding the car's mass, you can substitute it into the equation above to calculate the normal force.
(d) Similar to the normal force, you need the mass of the car to calculate the force of gravity (FG). The force of gravity acting on the car is given by:
Force of gravity (FG) = mass (m) × acceleration due to gravity (g)
Since the mass is not provided, you cannot find the exact value of the force of gravity. If you have the mass of the car, you can substitute it into the equation above to calculate the force of gravity.
Keep in mind that without the mass of the car or any additional information about it, it is not possible to calculate the exact values of the normal force and force of gravity.