Given :
You drive 200 miles in 3 hours before stopping for lunch and gas. After lunch you travel 250 miles in an hour and a half.
To Find :
Average speed.
Solution :
We know, average speed is given by :
Therefore, average speed of the journey is 100 miles/hr.
Hence, this is the required solution.
Answer:
Before:
After:
Explanation:
<u>Conservation of Momentum</u>
Two objects of masses m1 and m2 moving at speeds v1o and v2o respectively have a total momentum of
After the collision, they have speeds of v1f and v2f and the total momentum is
Impulse J is defined as
Where F is the average impact force and t is the time it lasted
Also, the impulse is equal to the change of momentum
As the total momentum is conserved:
We can compute the speed of the second object by solving the above equation for v2f
The given data is
a) The impulse will be computed at the very end of the answer
b) Before the collision
c) After collision
Compute the car's speed:
And the car's momentum is
The Impulse J of the system is zero because the total momentum is conserved, i.e. \Delta p=0.
We can compute the impulse for each object
The force can be computed as
The force on the car has the same magnitude and opposite sign
Answer:
θ₁ = 0.5 revolution
Explanation:
We will use the conservation of angular momentum as follows:
where,
I₁ = initial moment of inertia = 18 kg.m²
I₂ = Final moment of inertia = 3.6 kg.m²
ω₁ = initial angular velocity = ?
ω₂ = Final Angular velocity = = 1.67 rev/s
Therefore,
where,
θ₁ = revolutions if she had not tucked at all = ?
t₁ = time = 1.5 s
Therefore,
<u>θ₁ = 0.5 revolution</u>