The velocity of the brick is 39.2 m/s downward
Explanation:
The motion of the brick is a free fall motion, since the object is affected only by the force of gravity. Therefore, it has a uniformly accelerated motion towards the ground, with constant acceleration of .
So, we can find its velocity using the suvat equation:
where
v is the final velocity
u is the initial velocity
a is the acceleration
t is the time
For the brick in this problem (taking downward as positive direction)
u = 0 (it is dropped from rest)
Therefore, its velocity after t = 4.0 s is:
Downward, because the sign is positive.
Learn more about free fall motion:
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Answer:
The value of d is 20.4 m.
(C) is correct option.
Explanation:
Given that,
Initial velocity = 20 m/s
Final velocity = 0
We need to calculate the time
Using equation of motion
Where, u = Initial velocity
v = Final velocity
Put the value into the formula
We need to calculate the distance
Using equation of motion
Hence, The value of d is 20.4 m.
Answer:
22.2 m/s
Explanation:
First, we need to convert km to m by multiplying by 1000. This means that the car traveled 320 000 meters.
Next, we convert hours to minutes by multiplying by 3600 (the number of seconds in an hour). This means that overall, the car traveled 320 000 m in 14 400 seconds.
The average speed can be found by using the equation . After substitution, this gives the fraction
, which reduces to 22
m/s, or about 22.2 m/s.