False, <span>Nanotechnology is proving effective at helping clean up PCB’s.</span>
Answer:
a)Distance traveled during the first second = 4.905 m.
b)Final velocity at which the object hits the ground = 38.36 m/s
c)Distance traveled during the last second of motion before hitting the ground = 33.45 m
Explanation:
a) We have equation of motion
S = ut + 0.5at²
Here u = 0, and a = g
S = 0.5gt²
Distance traveled during the first second ( t =1 )
S = 0.5 x 9.81 x 1² = 4.905 m
Distance traveled during the first second = 4.905 m.
b) We have equation of motion
v² = u² + 2as
Here u = 0, s= 75 m and a = g
v² = 0² + 2 x g x 75 = 150 x 9.81
v = 38.36 m/s
Final velocity at which the object hits the ground = 38.36 m/s
c) We have S = 0.5gt²
75 = 0.5 x 9.81 x t²
t = 3.91 s
We need to find distance traveled last second
That is
S = 0.5 x 9.81 x 3.91² - 0.5 x 9.81 x 2.91² = 33.45 m
Distance traveled during the last second of motion before hitting the ground = 33.45 m
Answer:
F=5449 N
Explanation:
Work done is a product of force and displacement ie
Work done, W, = Force*Displacement
Power, P, is Work done/Time
where P is power, W is work done, F is force, S is displacement and t is time
In this case, F is the frictional force. Converting the power from hp to W, we multiply by 746 hence P=746*168=125328 W
Since displacement/time is velocity, then
P=FV where V is velocity in m/s
Making F the subject


F=5449 N
The second one is correct not sure about the first one sorry
Answer:
<h2>4.6 m/s²</h2>
Explanation:
The acceleration of an object given it's velocity and time taken can be found by using the formula
<h3>

</h3>
where
v is the final velocity
u is the initial velocity
t is the time taken
a is the acceleration
Since the body is from rest u = 0
From the question we have

We have the final answer as
<h3>4.6 m/s²</h3>
Hope this helps you