Answer:
Inclined Plane - A ramp, for example a wheelchair ramp to help move to another level.
Wheel & Axle - On lawnmowers and wheelbarrow.
Lever - A seesaw
Pulley - adjustable clothesline (think from back then when you would put clothes out to dry them)
Screw - the bottle caps you screw on or off
Answer:
a ) = 381.48 J
b )= 84.25 cm
Explanation:
Kinetic energy of the runner
= 1/2 m v²
= .5 x 66 x 3.4²
= 381.48 J
The final kinetic energy of the runner is zero .
Loss of mechanical energy
= 381.48 J
This loss in mechanical energy is due to action of frictional force .
b )
Let s be the distance of slide
deceleration due to frictional force
= μmg/m
.7 x 66 x 9.8 / 66
a = - 6.86 m s⁻¹
v² = u² - 2 a s
0 = 3.4² - 2x6.86 s
s = 3.4² / 2x6.86
= .8425 m
84.25 cm
Efficiency
Explanation:
Efficiency is a ratio/percentage that is useful in comparing the energy transferred by a device to the total energy supplied to it.
Percentage efficiency = 
x 100
- As with most system, none is 100% efficient.
- During energy is transferred some are lost and only a little portion is used in doing actual work by the machine.
- This validates the third law of thermodynamics which proposes that no system is 100% efficient.
- A 100% efficiency implies total energy input is used doing all the work.
- This is impossible. The bulk of the energy goes into heating the system.
learn more:
Third law of thermodynamics brainly.com/question/3564634
#learnwithBrainly
Answer:
414.9 m
Explanation:
First, become familiar with the horizontal, and vertical vector components.
Vertical vector: Vy = V × sin (θ).
Horizontal vector: Vx = V × cos(θ).
Distance traveled = Velocity vector × time in the air.
Time in the air given Vy = 2 × Vy / g (in respect to the metric of the vector).
Range of the projectile = Vx² / g
Time in the air given Vx = (Vx + √(Vx)² + 2gh) / g.
Given a 28° angle with an initial velocity of 70m/s, we have enough information to calculate!
Vx = 70 m/s × cos(28°) ≈ 61.806 m/s
Vy = 70 m/s × sin(28°) ≈ 32.863 m/s
t = 2 × Vy / g
t = 2 × ≈32.863 / 9.8
t = ≈65.726 / 9.8
t ≈ 6.7 s
Distance traveled (horizontal) = Vx × t = 61.806 × 6.7 ≈ 414.9 m
Answer:
0.695 m
Explanation:
α = angular acceleration of the fan blade = 14.1 rad/s²
a = tangential acceleration at the point concerned = acceleration due to gravity = 9.8 m/s²
r = distance of the point from axis of rotation at which tangential acceleration is same as acceleration due to gravity
We know the relation between
a = r α
Inserting the values
9.8 = 14.1 r
r = 0.695 m
