The last on on the image :-)
D = 1/2 x g × t²
145 = 1/2 × 9.8 × t²
t = 5.4 s
Explanation:
Newton's second law simply says that the net force on an object is equal to the object's mass times its acceleration.
∑F = ma
For example, think of a game of tug-of-war, in which two teams pull on a rope in opposite directions.
If the forces are equal (balanced), then the net force is 0 N, so Newton's second law tells us that the rope's acceleration is 0 m/s².
If the forces are not equal (unbalanced), then the net force is not 0 N, and the rope will accelerate in the direction of the net force.
If it is average speed per hour, then you just have to divide 3.5 into 60
60/3.5 = 17.143 so around 17km/h
p = mv so this question pertains to conservation of momentum.
The momentum of the car is 1320*12 = 15840kgms^-1
For the sake of easiness and the fact negatives are annoying, I will assume east to be positive.
So we know 9.4m - 15840 = (1320+m)*1.5
9.4m - 15840 = 1980+1.5m
Rearranging to solve for m
7.9m = 17820
m = 2255.70 = 2300kg to 2sf
