Answer:
Suppose two objects of different masses are moving with different velocities in the same direction on a straght-line before collision. After collision, they stick together and move with common (the same) velocity
Answer:
μk = 0.26885
Explanation:
Conceptual analysis
We apply Newton's second law:
∑Fx = m*a (Formula 1)
∑F : algebraic sum of the forces in Newton (N)
m : mass in kilograms (kg)
a : acceleration in meters over second square (m/s²)
Data:
a= -0.9 m/s²,
g = 9.81 m/s² : acceleration due to gravity
W= 75 N : Block weight
W= m*g
m = W/g = 75/9.8= 7.65 kg : Block mass
Friction force : Ff
Ff= μk*N
μk: coefficient of kinetic friction
N : Normal force (N)
Problem development
We apply the formula (1)
∑Fy = m*ay , ay=0
N-W-25 = 0
N = 75
+25
N= 100N
∑Fx = m*ax
20-Ff= m*ax
20-μk*100
= 7.65*(-0.90 )
20+7.65*(0.90) = μk*100
μk = ( 20+7.65*(0.90)) / (100)
μk = 0.26885
Answer:
Option B is the correct answer.
Explanation:
Let us consider 40 meter above ground as origin.
Initial velocity = 17 m/s
Final velocity = 24 m/s
Acceleration = 9.81 m/s
We have equation of motion v² = u² + 2as
Substituting
24² = 17² + 2 x 9.81 x s
s = 14.63 m
Distance traveled by rock = 14.63 m down.
Height of rock from ground = 40 - 14.63 = 25.37 m = 25.4 m
Option B is the correct answer.
Answer:
The final velocity of the car is 1.85 m/s
Explanation:
Hi there!
The initial kinetic energy of the toy car can be calculated as follows:
KE = 1/2 · m · v²
Where:
KE = kinetic energy.
m = mass.
v = velocity.
KE = 1/2 · 0.100 kg · (2.66 m/s)² = 0.354 J
The gain in altitude produces a gain in potential energy. This gain in potential energy is equal to the loss in kinetic energy. So let´s calculate the potential energy of the toy car after gaining an altitude of 0.186 m.
PE = m · g · h
Where:
PE = potential energy.
m = mass.
g = acceleration due to gravity.
h = height.
PE = 0.100 kg · 9.8 m/s² · 0.186 m = 0.182 J
The final kinetic energy will be: 0.354 J - 0.182 J = 0.172.
Using the equation of kinetic energy, we can obtain the velocity of the toy car after running up the slope:
KE = 1/2 · m · v²
0.172 J = 1/2 · 0.100 kg · v²
2 · 0.172 J / 0.100 kg = v²
v = 1.85 m/s
The final velocity of the car is 1.85 m/s