(a) The momentum of the first trolley is 5.4 kgm/s
(b) The velocity of the trolleys after impact is 2.7m/s
<u>Explanation:</u>
Given:
Mass, m₁ = 1.2kg
Velocity, v₁ = 4.5m/s
Mass, m₂ = 0.8kg
v₂ = 0
(a) Momentum of the trolley before impact, p
We know:
Momentum = mass X velocity
p = 1.2 X 4.5
p = 5.4 kgm/s
Therefore, the momentum of the first trolley is 5.4 kgm/s
(b) Speed of the trolleys after impact, v = ?
During collision, the momentum is conserved.
So,
m₁v₁ + m₂v₂ = (m₁ + m₂)v
(1.2 X 4.5) + (0.8 X 0) = (1.2 +0.8) X v
5.4 + 0 = 2v
v = 2.7m/s
Therefore, the velocity of the trolleys after impact is 2.7m/s
Because acceleration is not speed, and speed is not acceleration.
I'm sure you would not ask "Why isn't temperature given in acres,
as it is for area ?" Speed and acceleration are different things, so
it's only natural that they have different units.
The magnitude (size) part of acceleration is:
(how much speed changes) per second.
Are you speeding up ?
Are you traveling (2 meters per second) faster every second ?
Then your acceleration is
(2 meters per second) per second .
When you write that phrase as an algebraic expression, it's
(2 m/sec) / sec
and when you simplify that fraction, you get 2 m/sec² .
Average speed = (total distance covered) / (time to cover the distance)
Total distance = (77km + 66km) = 143 kilometers
Time to cover the distance = 2 hours
Average speed = (143 km) / (2 hours) = 71.5 km per hour
Answer:
At point A, the cart has high potential energy. At point b, the cart is pulled down by gravity. At point c, the cart gains its highest kinetic energy. At point d, the cart returns back to the same state but with lower potential energy.
