Answer:
19,551 J!
Explanation:
The formula is PE = ham (h=height, a= acceleration or 9.8, m= mass)
PE = (95)(9.8)(21)
PE = 19,551 Joules
Answer:
The flea will reach to a height of 5.2 cm.
Explanation:
Let us assume it is given that, a flea reaches a takeoff speed of 1.0 m/s over a distance of 0.50 mm.
Initial speed, u = 1 m/s
Initial distance, x = 0.5 mm
We need to find the height reached by the flea. Using third equation of motion to find it.
At maximum height, its final speed, v = 0

Here, a = -g

or
h = 5.2 cm
So, the flea will reach to a height of 5.2 cm.
Answer:
acceleration 8 km/h/s south
Explanation:
First of all, let's remind that a vector quantity is a quantity which has both a magnitude and a direction.
Based on this definition, we can already rule out the following two choices:
distance: 40 km
speed: 40 km/h
Since they only have magnitude, they are not vectors.
Then, the following option:
velocity: 5 km/h north
is wrong, because the car is moving south, not north.
So, the correct choice is
acceleration 8 km/h/s south
In fact, the acceleration can be calculated as

where
v = 40 km/h is the final velocity
u = 0 is the initial velocity
t = 5 s is the time
Substituting,

And since the sign is positive, the direction is the same as the velocity (south).
Answer:
90 N
Explanation:
The force applied to the ball is given by:

where
is the change in momentum of the ball
is the time taken
The change on momentum of the ball is:

So, the force applied is
