Acceleration = (change in speed) / (time for the change).
Change in speed = (15 - 30) = -15 km/hr
Time for the change = 4 sec
Acceleration = (-15 km/hr) / (4 sec) = -3.75 km/hr per second .
Is that a lot ? Not much ?
Let's convert it to a unit that we can think about:
(-15 km/hr) x (1,000 m/km) x (1 hr / 3,600 sec) =
(-15 x 1,000) / (3,600) = -(4 and 1/6) m/sec .
So the acceleration of the bus is -(4 and 1/6) m/sec² .
The negative sign means that it slowed down.
(4 and 1/6) m/sec² is about 42% of the acceleration of gravity ...
the acceleration the bus would have if it drove off of a cliff.
When the car or the bus you're riding in slows down at that rate,
you feel 42% of your weight pulling you forward against your
seat belt. That's quite a drastic acceleration !
Answer:
Acceleration, a = 0.5m/s²
Explanation:
Given the following data;
Force, f = 20N
Mass = 40kg
To find the acceleration;
Force is given by the multiplication of mass and acceleration.
Mathematically, Force is;
Where;
F represents force.
m represents the mass of an object.
a represents acceleration.
Making acceleration (a) the subject, we have;
Substituting into the equation;

Acceleration, a = 0.5m/s²
Therefore, the acceleration of the bookcase is 0.5m/s²
Answer:
Part a)

Part b)
East of South
Explanation:
Part a)
Velocity of Juan is given as

velocity of the ball is given as

now we have

Part a)
We need to find velocity of ball with respect to Juan
so it is given as



magnitude of the speed is given as


Part b)
direction of velocity of the ball


East of South