Answer:
4
Explanation:
The weight of the rock is W = mg = (80 kg) (10 m/s²) = 800 N.
The mechanical advantage is therefore 800 N / 200 N = 4.
Explanation:
Below is an attachment containing the solution.
Explanation:
Given that,
The initial velocity of a skater is, u = 5 m/s
She slows to a velocity of 2 m/s over a distance of 20 m.
We can find the acceleration of skater. It is equal to the rate of change of velocity. So, it can be calculated using third equation of motion as follows :

a = acceleration

So, her acceleration is
and she is deaccelerating. Also, her initial velocity is given i.e. 5 m/s.
Answer:
a. a=33.34ms⁻², V=164.4m/s
Explanation:
Since the dragster started with zero velocity, de determine the acceleration using of the equations of motion.
Below are the data given
Distance, s=404.5m,
time taken,t=4.922secs
Using the equation
S=ut+1/2at²
where u is the initial velocity and u=0
Making the acceleration the subject of the formula, we arrive at
a=2s/t²
a=(2*404.5)/4.922²
a=33.34ms⁻².
To determine the velocity, we use
V=u+at
V=0+33.34ms⁻² *4.922sec
V=164.4m/s
Answer:
The smallest diameter is 
Explanation:
From the question we are told that
The resolution of the telescope is 
The wavelength is 
From the question we are told that

So 
Therefore


Now 
So 
=> 

The smallest diameter is mathematically represented as

substituting values

