How Long Does It Take for a Car to Catch Up to a Truck?

  • Thread starter Thread starter muktl
  • Start date Start date
  • Tags Tags
    Kinetic Velocity
AI Thread Summary
To determine how long it takes for a car traveling at 90 km/h to catch up to a truck moving at 50 km/h, start by defining the position equations for both vehicles. The car's position can be expressed as P_car = 90t, while the truck's position, accounting for the initial 100m lead, is P_truck = 50t + 100. Setting these equations equal to each other allows for the calculation of time when both vehicles meet. Solving the equation 90t = 50t + 100 will yield the time required for the car to catch up. The final answer reveals the duration needed for the car to reach the truck.
muktl
Messages
6
Reaction score
0
a car is going at 90 km/h

a truck is 50 km/h

the car is 100m behind the truck

so how long does the car need to reach to the truck?
 
Physics news on Phys.org
This should be in the homework help section. but first try writing an equation for the position of the car as a function of time and then write an equation for the position of the truck as a function of time plus 100m (this way the position of the truck is relative to the initial position of the car). Now, when they meet they meet at the same time and the same position so then simply equate the two equations to find the time.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top