Answer:
The velocity of the boy and the bicycle is 2.2 m/s.
Explanation:
We have,
Mass of child is 30 kg and the mass of bicycle is 20 kg. The combined momentum of the child and the bicycle is 110 kg-m/s.
It is required to find the velocity of the boy and the bicycle. The momentum of an object is given in terms of mass and its velocity. So,
M is combined mass of child and bicycle
So, the velocity of the boy and the bicycle is 2.2 m/s.
Answer:
Magnitude of the Frictional force = (mv₀²)/2x₁
Explanation:
For the frictional force to stop the box, it has to produce the deceleration of the box; thereby being the opposing force to the box's motion.
According to Newton's first law of motion
Frictional force = (mass of the box) × (deceleration experienced by the box)
Let the mass of the box be m
Then,
Frictional force = ma
Then we can obtain the deceleration using the equations of motion
v² = u² + 2ax
u = Initial velocity = v₀ m/s
v = Final velocity = 0 m/s (since the box comes to rest at the end)
x = horizontal distance covered = (x₁ - x₀) = x₁ (since x₀ = 0)
a = ?
v² = u² + 2ax
0 = (v₀)² + 2ax₁
2ax₁ = - v₀²
a = - (v₀²)/(2x₁) (minus sign, because it's a deceleration)
Magnitude of the Frictional force = ma = (mv₀²)/2x₁
No. She would be doing the same amount of work that way. Work is defined to be equal to the force multiplied by the distance. Carrying two bags at a time would cause her to exert twice the effort, so the total amount of work done in the end would still be the same.
Answer:
7200 kg.m/s
Explanation:
According the law of conservation of linear momentum, the sum of momentum before and after collision are equal.
Using this principle, the sum of initial momentum will be given as p=mv where p is momentum, m is mass and v is velocity
Initial momentum
Mass of whale*initial velocity of whale + mass of seal*initial seal velocity
Since the seal is initially stationary, its velocity is zero. By substitution and taking right direction as positive
Initial momentum will be
1200*6+(280*0)=7200 kg.m/s
Since both initial and final momentum should be equal, hence the final momentum will also be 7200 kg.m/s
Answer:
Explanation:
m = Mass of object = 
mg = Weight of object = 20 N
g = Acceleration due to gravity = 
v = Final velocity = 15 m/s
u = Initial velocity = 0
d = Distance moved by the object = 150 m
= Angle of slope = 
f = Force of friction
fd = Work done against friction
The force balance of the system is
The work done against friction is .
