Answer:
(a) the blocks all had different masses.
Explanation:
The surface is smooth, therefore coefficient of friction is tending to zero.
Forces for each blocks varied from 6N to 8N to 7N to 5N
The blocks were made of different materials and different materials are going to have varying weight for the same size of block.
Answer:
4. Downward and its value is constant
Explanation:
As this is a case of projectile motion, we use the reference frame where upward direction to be positive for 
, and in the same way to be negative in the downward direction. On another hand, we have that gravity is always acting this means that gravitational acceleration g is directed downward constantly over the dart not only during the upward but also during the downward part of the trajectory. And it is ruled by the following equations.
For the x-axis
For the y-axis
Where 
, is the initial velocity.
Answer with Explanation:
We are given that
a.We have to find the expression for the minimum thickness the film can have ,t.
Condition for destructive interference
For minimum thickness m=0
Then, 
b.Substitute the values
Answer: 21 N
Explanation:
Force=mass x Accceleration
So 21=3x7
Answer:
speed = distance / time
Explanation:
speed = 495 km /4.5 hours
=110 km /h
