Answer:
Explanation:
As we know that the distance moved by the car is given 300 km
first it move for 120 km with speed
v = 100 km/h
so the time taken by car to move this distance is
Now it moves next 43.0 km with speed 42 km/h
so the time taken by it is given as
now total time of journey is
time remaining to cover the last part of journey is
now the remaining distance is
so the speed of the car is given as
Answer:
a) The object must have constant velocity.
d) The object must have zero acceleration.
Explanation:
We can solve the problem by using Newton's second law, which states that the net force acting on an object is equal to the product between mass and acceleration:
where
F is the net force
m is the mass of the object
a is the acceleration
In this problem, the net force on the object is zero:
F = 0
This means that the acceleration of the object is also zero, according to the previous equation:
a = 0
So statement (d) is correct. Moreover, acceleration is defined as the rate of change of velocity:
Which means that , so the velocity is constant. Therefore, statement (a) is also correct. The other two statements are false because:
b)The object must be at rest. --> false, the object can be moving at constant velocity, different from zero
c)The object must be at the origin. --> false, since the object can be in motion