Answer:
a and b are the correct answers
Explanation:
Brake-pads in cars. The scratching strip on the side of a matchbox. The ridges on the soles of snow-boots.
Answer:
v₁ = 0.45 m/s or v₂ = -0.10 m/s
Explanation:
Marble 1 has a mass of m and an initial velocity of -0.30 m/s.
Marble 2 has a mass of m/2 and an initial velocity of 0.80 m/s.
Momentum is conserved, so:
m (-0.30) + m/2 (0.80) = m v₁ + m/2 v₂
-0.3m + 0.4m = m v₁ + m/2 v₂
0.1m = m v₁ + m/2 v₂
0.1 = v₁ + 1/2 v₂
One of the marbles has half the speed after the collision. Let's first assume that it's Marble 1. That means v₁ = -0.15 m/s or 0.15 m/s.
If v₁ = -0.15 m/s:
0.1 = -0.15 + 1/2 v₂
0.25 = 1/2 v₂
0.5 = v₂
This isn't possible; at least one of the marbles must change direction.
If v₁ = 0.15 m/s:
0.1 = 0.15 + 1/2 v₂
-0.05 = 1/2 v₂
-0.1 = v₂
This is a possible solution.
Now, let's assume that Marble 2 is the one that moves at half the speed. That means v₂ = -0.40 m/s or 0.40 m/s.
If v₂ = -0.40 m/s:
0.1 = v₁ + 1/2 (-0.40)
0.25 = v₁ − 0.2
0.45 = v₁
This is a possible solution.
If v₂ = 0.40 m/s:
0.1 = v₁ + 1/2 (0.40)
0.1 = v₁ + 0.2
-0.1 = v₁
This isn't possible; at least one of the marbles must change direction.
Therefore, there are two possible answers: v₁ = 0.45 m/s, or v₂ = -0.10 m/s.
Answer:
c) those caused by parasites
Answer:
1. What force does the trailer exert on the car? = 696 Newtons
2. -696 Newtons are acting on the car.
Explanation:
1.Calculate the force exerted by the car on the trailer.
The expression for the force from Newton’s second law is, F=ma
Substitute 580kg for m and 1.2m^2
F=(580kg)(1.20m/s^2 = 696N
2. According to Newton’s third law, an equal force is exerted by the trailer in the opposite direction. Hence, the magnitude of the force is negative.