Answer:
An object can have a displacement in the absence of any external force acting on it
Explanation:
When a object moves with a constant velocity (v), then it gets displaced in the direction of motion but the net external force experienced by the object is zero.
F external =ma
If object moves with constant velocity, acceleration is zero.
Since, a=0 ⟹F external =0
Using s=ut+ 1/2 at ^2
⟹ Displacement s=ut (∵a=0)
Hence, an object can have a displacement in the absence of any external force acting on it
Hope this helped you:)
Answer:
Friction is a force that opposes motion.
Answer:
68 readings.
Explanation:
We need to take this problem as a statistic problem where the normal distribution table help us.
We can start considerating that X is the temperature of the solution, then



For a confidence level of 90% our
is 1.645
Therefore,

Substituting for
and re-arrange for n, we have that n is equal to




We need to make 68 readings for have a probability of 90% and our average is within 
Answer:
θ = 41.80°
Explanation:
Given that
Mach number M= 1.5
We know that
M = u/c
Where c is the velocity of sound and u is the speed of plane
c= 340 m/s
So
u = 1.5 x 340 m/s
u = 510 m/s
We know that

Now by putting the values


θ = 41.80°
So the angle will be 41.80°.