Answer:
Explanation:
Remark
In general, these 3rd class levers are very inefficient. Because the force distance is smaller than the load distance, you need to pull upward with more force that the weight of the load. So whatever the load is, the force is going to be much greater.
The distances are always measured to the pivot unless you are asked something specific otherwise.
Givens
F = ?
weight = 6N
Force Distance = F*d = 0.5 m
Weight Distance =W*d1 = 2 m
Formula
F*Fd = W*Wd
Solution
F*0.5 = 6 * 2 Divide by 0.5
F = 12/0.5
F = 24 N upwards
<h2>
<u>KINETIC ENERGY</u></h2>
<h3>Problem:</h3>
» A 2kg mass is moving at 3m/s. What is its kinetic energy?
<h3>Answer:</h3>
— — — — — — — — — —
<h3>Formula:</h3>
To calculate the velocity of a kinetic energy, we can use formula
where,
- v is the velocity in m/s
- KE is the kinetic energy in J (joules)
- m is the mass in kg
— — —
Based on the problem, the givens are:
- KE (Kinetic energy) = ? (unknown)
- m (mass) = 2 kg
- v (velocity) = 3 m/s
<h3>Solution:</h3>
To get the velocity, substitute the givens in the formula above then solve.
Therefore, the kinetic energy is 9 Joules.
Momentum = mass x velocity
Thus Option A is the correct answer
Momentum (dog) = 10 kg x (0.447 x 30) m/s
= 134.1 Kg m/s
Momentum ( bullet) = 0.02 kg x (0.447 x 800) m/s
= 7.152 Kg m/s
Momentum ( truck) = 0, as v = 0
tightrope has both low mass and low speed, thus its momentum will be low
