Answer:
C Don't worry if you thought it was D. I almost answered that.
Explanation:
Remark
You can get this just by learning the vocabulary.
Efficiency = Work Out / Work In * 100%
Work in = 30J That's you swinging the hammer.
Work out = 10 J That's how much of the hammer's work gets to the nail.
Efficiency = (10/30)*100
Efficiency = 1/3 * 100
Efficiency = 33%
Power is the rate of doing work or using energy.
The unit of power is the watt.
1 watt = 1 joule per second
It is used to classify the climates around the world
Answer:
10 m/s
Explanation:
Use the kinetic energy formula:
KE=(1/2)mv^2
I always remember it as Kevin is half-mad, and very square.
25J = (1/2)*0.5kg*(v^2)
50J = 0.5kg*(v^2)
100J = v^2
v = 10 m/s
Check it:
KE = (1/2)*0.5*(10^2)
KE = 25J
yep, it's right!
Answer:
A. less
Explanation:
The momentum of an object is directly proportional to it mass and velocity. It is the product of mass and velocity of the object. Given as

So the momentum of car,

Momentum of truck,

We know that, mass of car is less than that of truck and velocity of the two are same. It is implied that, momentum of car will be less than that of truck.