Answer:
C. 4.0 J
Explanation:
Work is equal to the change in kinetic energy or kinetic energy final - kinetic energy initial. 1/2 mv^2 is the equation for kinetic energy. SInce the mass is the same, you don't have to include it when solving. 1/2 times 1^2 = 1/2. 1/2 times 3^2 = 4.5. 4.5 - 0.5 = 4 J
Answer:
m=1000kg
v=72km/h=20m/s
Work = different of kinetic energy
W= ½ mv ²
W= ½ ×1000×20×20= 400000J
also written as 4×10^5 J
thank you
Answer:
b. -11.6 cm
Explanation:
We have given parameters:
Length, l = 1.5 m = 150 cm
Mass of weight, 
= 20 kg
Width, x = 4 cm
Distance d = 4 cm
Mass of bar, 
= 5 kg
We are asked to find the center of mass from the mid-point, 
Since 3 weights are on the left and 2 weights are on the right, we know:
= 3 * 20 = 60 kg
= 2 * 20 = 40 kg
And also we know that, 
= 150/2 = 75 cm
For the left side, center of mass is:
cm
From the midpoint, the distance to the left is:
cm
For the right side, center of mass is:
cm
From the midpoint, the distance to the right will be:
cm
Hence,
cm
Answer:
The hammer and the wall exert forces on each other that are equal in magnitude but in opposite directions.
Explanation:
currently doing corrections on the test!
:)
