Q1.
(a) A car accelerates at a constant rate of 1.83 m/s? along a flat straight road.
The force acting on the car is 1.870 KN.
Calculate the mass of the car.
Give your answer to three significant figures.
mass =
(b)
The car accelerates from rest for 16s.
Calculate the speed of the car after 16s.
speed=
(c)
The car starts on another journey. Figure 6 shows the graph of the car’s movement. (Figure at top)
Show that the distance travelled when the car is moving at a constant speed is greater than the distance travelled when the car is slowing down.
a) force = mass • acceleration Convert: 1.870 KN -> 1870 N 1870N = mass • 1.83 m/s^2 ———- —————- 1.83 m/s^2. 1.83 m/s^2 -> approx. 1,021.9 grams :D
b) Vi = Vf - at 0 m/s = Vf - 1.83 m/s^2 • 16s 0m/s = Vf - 29.28 +29.28 + 29.28 Vf = 29.28 m/s :D
c) x = Vi + 1/2 • at^2 A to B T= 15s Vi = 16m / s A = 1.83m/s^2 x= 16 + 1/2 • 1.83(15)^2) x = approx. 221. 9 meters
C to D T = 9s Vi= 30m/s x = 30 + 1/2 1.83(9)^2 x= approx. 104.1 meters
Therefore, when the car is moving at a CONSTANT RATE, it’s traveling farther than when slowing down cause it travel 221.9 meters while slowing down, it’s going only 104.1 meters.
