work done is product of force and displacement of point of application of force
so here we have to check the product of force and displacement both
Now we will put the least to maximum work in the following order
1. -A man exerts strenuous effort in pushing a stationary wall
2. -A flea pushes a speck of dirt 1 cm
3. -A farmer pushes a 2 kg wheelbarrow 20 m
4. -A cannon launches a 3 kg cannonball a distance of 200
5. -A 2000 kg car travels 400 m down a road
6. -Space shuttle Atlantis launches from the ground into near-Earth orbit
Look at the first person’s answer. Cause I know I’m wrong
Answer:
Vf = 69.56 cm/s
Explanation:
In order to find the final speed of the ramp, we will use the equations of motion. First we use second equation of motion to find out the acceleration of marble:
s = Vi t + (1/2)at²
where,
s = distance traveled = 160 cm
Vi = Initial Speed = 0 cm/s (since, marble starts from rest)
t = time interval = 4.6 s
a = acceleration = ?
Therefore,
160 cm = (0 cm/s)(4.6 s) + (1/2)(a)(4.6 s)²
a = (320 cm)/(4.6 s)²
a = 15.12 cm/s²
Now, we use first equation of motion:
Vf = Vi + at
Vf = 0 cm/s + (15.12 cm/s²)(4.6 s)
<u>Vf = 69.56 cm/s</u>
Answer:
896 kJ
Explanation:
KInetic Energy = 1/2 m v^2
= 1/2 (1120)(40^2) = 896 000 J or 896 kJ
