Answer:
Different street blocks are different lengths, so it won't be possible to answer this.
Answer: 4.77m/s
Explanation:
According to the law of conservation of momentum which states that the sum total of momentum of bodies before collision is equal to the sum of their momentum after collision. Note that the two bodies will move at a common velocity after colliding.
Let m1 and m2 be the mass of the first and second railroad cars
u1 and u2 be the velocities of the railroad cars
v be the common velocity
Using the formula
m1u1 + m2u2 = (m1 +m2)
m1 = 1.20×10⁴kg
m2 = 1.20×10⁴kg (body of same mass)
u1 = 7.70m/s
u2 = 1.84m/s
v = ?
(1.20×10⁴×7.7) + (1.20×10⁴×1.84) = (1.20×10⁴ + 1.20× 10⁴)v
9.24×10⁴ + 2.21×10⁴ = 2.4×10⁴v
11.45×10⁴ = 2.4×10⁴v
v = 11.45×10⁴/2.4×10⁴
v = 4.77m/s
The velocity of the cars after collision will be 4.77m/s
Answer:
The acceleration of the total mass decreases by half (1/2)
Explanation:
Given;
acceleration of sled = 2 m/s²
From Newton's second law of motion, F = ma
⇒m = F/a
F is the force applied by Jenny
This force applied by Jenny should be the same, after Tommy jumps on the sled, but the acceleration will change.
F = m₁a₁ = m₂a₂
Since m₂ = 2m₁, then we calculate a₂
m₁a₁ = 2m₁a₂
a₂ = a₁/2
Therefore,The acceleration of the total mass decreases by half.
Answer:

Explanation:
Given that,
The instantaneous current in the circuit is giveen by :

We need to find the rms value of the current.
The general equation of current is given by :

It means, 
We know that,

So, the rms value of current is 2.12 A.
Answer:
Velocity has a direction associated with it, while speed has no specific direction.
Explanation:
Velocity is a vector, while speed is a scalar.