From the change of GPE into KE. Conservation of energy tells us this.
♥ C) 94%
♥ If the work put into a lever is 930 joules and the work accomplished is 870 joules, the efficiency of the lever is 94%.
♥ <span>870/930=93.5
</span>♥ And rounded you get 94.
To solve this problem we will apply the concepts related to Ohm's law and Electric Power. By Ohm's law we know that resistance is equivalent to,

Here,
V = Voltage
I = Current
While the power is equivalent to the product between the current and the voltage, thus solving for the current we have,


Applying Ohm's law


Therefore the equivalent resistance of the light string is 
Answer:
11.0 kg m/s
Explanation:
The impulse exerted on the cart is equal to its change in momentum:

where
m = 5.0 kg is the mass of the cart
is its change in speed
Substituting numbers into the equation, we find

Answer:
(a)
(b) It won't hit
(c) 110 m
Explanation:
(a) the car velocity is the initial velocity (at rest so 0) plus product of acceleration and time t1

(b) The velocity of the car before the driver begins braking is

The driver brakes hard and come to rest for t2 = 5s. This means the deceleration of the driver during braking process is

We can use the following equation of motion to calculate how far the car has travel since braking to stop


Also the distance from start to where the driver starts braking is

So the total distance from rest to stop is 352 + 88 = 440 m < 550 m so the car won't hit the limb
(c) The distance from the limb to where the car stops is 550 - 440 = 110 m